ilS) im • m - m = a - m S CD = a s CD S rn = D ^ o DEPARTMENT OF THE INTERIOR. REPORT UNITED STATES GEOLOGICAL SURVEY THE TERRITORIES. F. V. HOYDEN, UNITED STATES GEOLOGIS T-I N-CHAEGE VOLUME III. WASHIJSGTOlsr: GOVERNMENT FEINTING OFFICE. 18 84. :n^ote. Department of the Interior, United States Geological Survey. On the 27th of September, 1882, at the request of Dr. F. V. Hay den, the completion of the pubHcations of the United States Geological and Geographical Survey of the Territories, formerly under his charge, was committed to the charge of tlie Director of the Geological Survey by the following order from the honorable the Secretary of the Interior : Department of the Interior, Washinffton, Septemher 27, 1882. Maj. J. W. Powell, — Director U. S. Geological Stirvei/, Citi/: Sir: The letter of Prof F. V. Hayden, dated June 27th, bearing your indorsement of Jul}* 20th, relating to the unpublished reports of the sur- vey formerly under his charge, is herewith returned. You will please take charge of the publications referred to in the same, in accordance with the suggestions made b}' Professor Hayden. It is the desire of this office that these volumes shall be completed and published as early as practicable. Very respectfully, H. M. TELLER, Secretari/. Of the publications thus placed in charge of the Director of the Sur- ve}^, the accompanying volume is the first to be issued. It is understood that its preparation was begun in 1871-', by the transmission of a part of the manuscript to the Public Printer. (iii) IV NOTE. At the tiuie wIr'U tlit- wcnk was tunitd over to the Director oi' the Geological Survey an important portion of the manuscript was yet unpra- pared ; l)ut, throui^h tlie energy of Professor Cope, the volume has been raj)idlv brought to eomjjletion. Tlie work coustitutcs a vahiable oontrilm- tioii to |iak-()iitology, and is a iiiniminent to the labor and genius of the authoi- and to the administrative talent of Di' llavden. 1 lie yet unpublished volumes will be pushed to completion at an earlv day. Director U. S. Geological Survey. Washington, September II, 1883. / ^-/ LETTER OF TRANSMITTAL- \ Washington, January 1, 1883. Sir: I have the honor to transmit for 3-onr approval the third vohnne of the series ot final reports of the United States Geological Survey of the. Ter- ritories, which during its existence was nnder my charge. Tlie present volume, which has been prepared by the eminent paleon- tologist. Prof K. D. Cope, of Philadelphia, represents the labor of several years, both in the field and in the study, and may l)e regarded as one of the most important contributions to the rich field of vertebrate paleontology of the western Territories ever made in this country. It was the original purpose to include all the material in the author's possession from the Cenozoic and Mesozoic formations in the third and fourth volumes of the series, but they accumulated to such an extent that it became necessary to limit them to the Cenozoic alone. Therefore, the two volumes are essentially one in subject matter. This volume consists of 1002 pages of text, illustrated with more than one hundred plates, and the fourth volume, which is to follow, may be regarded as a continuation of the present one, both comprising the material in the author's possession from the Cenozoic formations of the West. The two volumes are divided into four parts, viz: Part I, Puerco, Wasatch, and Bridger Faunse (Eocene); Part II, White River and John Day Faunse (Lower and Middle Miocene) ; Part III, TicholejDtus and Loup Fork Faunse (Upper Miocene); and Part IV, Pliocene. vi LETTER OF TRANSMITTAL. The present volume includes Part I, and the first j)ortion of Part II as far as the Ungulates; including, therefore, the Marsupials, Bats. Insectivores, Rodents, and Garni vora of the Miocene. Part I includes the folh)winL'' ninst important contrihutions to paleon- tology and evolution: 1. The discovery of the fauna of the Puereo Gruu)), <>f thirty genera and sixty-three species. This includes many important details, such as the discovery and definition of three new families, with many species of a new order, the Taxeopoda, as the PeripUfchidcE, Meniscotheriidce, and a new sub- order, the Taliffrada, represented li\' tlie genus Pantolamhda ; also the dis- covery of the Plagiaulax type (of the Jurassic) and other Marsupials, and the Laramie Saurian genus Champsosaurus in the Puerco Group. 2. The new classification of the Ungulata rendered possible by the dis- covery of the complete remains of the Wasatch types of Pheuacodns and Coryphodon, especially the former, from Wyoming Territory. The light thrown on the phylogeny of the Ungulata by this discovery exceeds that derived from all other sources together. 3. The new classification of the lower clawed niaimnals, liased on the analyses of fifteen new genera- and forty-seven new species of fiesh-eaters, and six new genera and sixteen new species of allied forms, all discovered since the publication of the author's volume in connection with the Wheeler Survey. 4. The restoration of Hyracotherium, the four-toed horse of the Wasatcli Group. h. The restoration of the genera TripU)piis and llyracliyus of the Bridger Fauna. 6. The detenniiiatidii of tiu; systematic relation of the Dinocerata as seen in the genera Loxolojihodon and Bathyopsis. The wiiole mnnber of genera described in this volume is 125, and of species .■J4!i, of which 317 species were determined by Professor Cope. The explorations that furnished the materials for these volumes began in 1872, and are still being continued. If will tlierefore be readily seen that the amount of new matter towards tlie origin ami history of the Mam- LETTER OF TRANSMITTAL. Vll malian group brought together by the author iu these two volumes is most extraordinary, and will probably never be surpassed. The plates which illustrate this volume were engraved by Thomas Sin- clair & Son, of Philadelphia, and the figures were drawn on stone from the specimens themselves, under the immediate supervision of Professor Cope. At the close of the fiscal year ending June 30, 1882, at my request, the Secretary of the Interior placed the printing of the uncompleted vol- umes of the quarto series in the care of Maj. J. W. Powell, the Director of the United States Geological Survey, and I desire him to accept my cordial thanks for his very kind attention and for many personal courtesies. Very respectfully, your obedient servant, F. V. HAYDEN, United States Geological Survey of the Territories. The Hon. the Secretary of the I^TERIOR, Washington, D. C. UNITED STATES GEOLOGICAL SURVEY OF THE TERRITORIES. THE VERTEBRATA TERTIARY FORMATIONS OF THE ^V^^EST. Book I. By EDWARD D. COPE, MEMBER OF THE NATIONAL ACADEMY OF SCIENCES. WASHINGTON: GOVERNMENT PHINTINO OFFICE. 1883 . CONTENTS, Page. Letter of transmission xx Proftice xxiii INTRODUCTION. Section I. The Tertiary Formations of the Central Region of the United States 1 TliePiiorco- 4 The Wasatcb iJ Tlie Bridger 11 Tlie Uiuta 1^ The Wliite River 13 The Loiip Forlv 16 TheEquus Betls 19 Section II. Thi; Horizontal Relations of the North Americ-vn Tertiaries with those of Europe. . '27 r A KT FIRST. The Puerco, Wasatch, and Bridger Faun^ 40 Pisces 49 Ela.snioliranchi 49 Xiphotrygon 49 Xipbotrygon acutidens 50 Ginglymodi 52 Clastes 53 Clastes anax 53 atrox 54 cycliferus 54 ciiueatiis 55 Hali'coniorphi .56 Pappichtliys • 56 Pappichtliys solerops 57 liC'vis 58 jjlicatns - 59 corsoni 60 Neniatogiuithi 61 Rhineastes 62 Rbineastps peltaUis 63 sniithii 64 c al vTis 65 arcuatiia GG Taduhi.s 67 Isospondy li 67 xi 5^5^0 Xn CONTENTS. The Pukrco, Wasatch, Axn Dridgkr Fauk^— Continued. Pisces : Poze. Daprdiiylossiis W Da|)cdoglossu8 cnoaustus 70 testis "1 acutus "2 tequipinuis '<3 Diplumystus "•! Diploniystus clcntatus *4 anulis "5 pcctorosns 76 theta "7 liiimilis 77 alius 79 Percomorpbi 79 Erisuiatoiilerus SO Erisniatoptenis levatus 80 rickseekeri 81 endlichi 82 Auiphipla'^a 83 Anipbiplaga brachyptera 84 Asiucops 84 Asiucops squamifrons 85 panel radiatus 87 Mioplosus 88 MioplosuH abbreviatns 83 labracoides 89 longus 90 bcani 91 sau vageanus 92 Priaoacara 92 Priscacara scrrata 93 cy pba 94 oxy prion 94 olivosa 96 pealci 96 Hops 97 testudiuaria 98 Batrachia 100 Rcptilia 101 Opbidia 102 Protagras 102 I'rotagras lacustris lOJ Laot^rtilia • 104 Chori.ttodcra 104 Cbanipsosanrus 1H4 ChainpHosannm australis 107 pucrconsis 107 saponeusis 109 Testndinala Ill Axcstus 116 Axnstus byssinns 116 Trioiiyx 117 Triouyx radnlus 119 fjnttatus 119 betrroglyptns 120 CONTENTS. XI li The Puerco, Wasatch, and Bridgek Faun^ — Continued. Eeptilia : Page. Triouyx coiicentricus liiO soutiimantiquum 121 Plastomeuus 1^2 Plastomenus trionychoides Id^ multifoveatus 124 molopinus V& cedemius 126 Anostira 127 Anostira radulina 128 oriiata 128 Emys 12» Emys polycypha 131 - terrestris 131 megaulax 132 euthnel a 133 testiidinea 134 vyoiniiigeusis 135 shaugbuessiana 135 hay deiii 137 l.atilabiatus 138 septaria 139- Hadriamis 140 Hadrianus allabiatus 140- octonaiius 140 corsoni 141 Dermatemys 142 Dcrmatemys vyomingensis 142 Notomorpha ■ 142 Notomorpha gravis 143 Baeiia 144 Bauiia Lebraiea 146 uudata 147 areuosa 148 ponderosa -T 150 Crocodilia 151 Crocodilus 151 Crocodilus subulatus ]. . 152" polyodou 154 acer 154 sulciferus 157 clavis 157 affiuis 102' hetcrodon I(i4 Mammalia I'j'^ M.irsnpialia ^. 1(|7 Catopsalis 170 CatopsaJis foliatus - 171 Ptilodus ■- 172 Ptilodus medisBVUs 173 Rodeutia 175 Plesiaixtomys 1^5 Plesiarctomys buccatus 179 delicatissimus l''J delicatior lf'2' XIV CONTENTS. The PvKitco, Wasatch, and BRiDGEB.FAUNiE^-Goiitinned. Muiuiiialia : Pagi'. ISiuiutburiu I'io TuiuindoDta 187 Culaiiiodou - ItSe Calaraodou simples Iftt cylindriler 192 Ta-niolabis 193 T;i-niolal>is scalper 193 Tillodouta 194 Psittacotherium 19r> Psittacotlieriiini niultilragum 196 aspasiaj 190 Insect ivora 19* Couory ctes 198 Conoryctes comma 19s crassicuspis 201 Estboiiyx 202 Esthoiiy X biirmeisteri 204 acutidcus 210 spatulariiis 211 "Mesodnuta 211 Microsyops 21C Microsyops spierianus 21(> elogans 217 scottianus 217 Toniitlicriuiii 218 Tomitberiuiii rostratum 221 Pelycodus 224 Pelycodiis pclvidens 225 jarrovii 228 t utus 228 Irugi vorus 230 augulatus 231 Sarcolemur 233 Sarcolemur pygma;us 233 Hyopsodus 234 Hyopsodiis powelliauus 235 leuiuiuiaiiiis 236 ])aiiliis 2il7 vioarius 237 iuolytns 238 Prosiiiiis 239 Mixodcctc8 240 Mixodectes jmiigeus 24 1 rrassitisculus 242 Cynodonloiiiys 243 Cyiiodoiitomys latidons 244 Aiiaptoniorphiis 24."> Aiiapt(>iii(ir|>liiiH lumiilus 248 liomunculns . 249 Creodonta 251 Ictops 265 Ictops bicuspis 2'i6 didelplioides 2t>s CONTENTS. XV The Puerco, Wasatch, and Bridgeu Faun^— Continued. Mammalia: Page. Peratherium .■ ; j ~6tf P«ratherium comstocki 2G0 Tri'isodou ......;. '-i'i> Triisodon quivireusis , i2T2 heilpriuianus '27'.i levisanus ^ 273 eonidens ^ ^... — 274 Deltatherium - . 277 Deltatberiura fundamiuus »■. i 278 baUlwiui ^ 232 interrupt lira -. 2ri2 Didtlphodus ---- 283 Didelphodus absarokce 284 Styiwlopbus ....1. 283 Stypolophus insect! vorus 290 pungeus 291 brevicalcaratus - -.- 291 wbitia? 292 aeuleatus 299 Miaois - - 301 Miacis canavus 3il2 brevtrostris 30;1 parvivorus - 304 Didymictis.. 304 Didymictis baydeuianus ^. 30Ci altidens 307 leptomyliiB 309 dawkin--ianus 310 protenus 311 Oxyseua 313 Oxyrena foreipata - 31m Protopsalis 321 Protopsalis tigrinus 32v! Mioclienus 324 Mioclcenus t urgidus 32.'i minimus 327 baldwini 32>i feros . - 32.~ subtrigouus 338 mandibularis 339 protogonioides 341 1 bucculeutus 341 coiTuj;atus 341 Acbsenodou 342 Acb;vnodou insolens 343 Dissacus 344 Dis.s;K'Ud navajuvius , 34.") caruifex 345 Sarcotbraustes 34 i Saicotliraustes antiqnus 347 Mesonys 34~ Mesony.K obtusidens - 3:3 lanlns 358 ossifragus SC- XVI CONTENTS. TiiK PfERCo, Wasatch, AXr> Bitiixii-ii Faun^— Continued. Maoiiuuli.t : Page- CbiruiitiT.i 3T:t- WspcTiigo :$T3 Vf»|iiTiigo ancmopUilus 374 Tiixi'opoda 374 Tuxeopodii 37"^ Proboseidi a :r79- Amblypodu 37"> Uiplarthni 37> Condylarlbra :iS-> Periptj'cliiduj itiS,') Plu'iiatodoiitiiUi' 3!:6 Meniscotlieriida; IJgO. Pt-ripljcUus 387 Pt-ript ychus lUabdodoii 3f?i> cariiiideUH 405 di(rigonu8 404 lK-niilUKeii» 405 Heiiiitbla;u8 kowalevskiaiius 40.> opiiitbacuH 407 AuisuucUiis 408 AnisoiicbuN coiiifenis 409" );illiaiiu8 411 Kcctorius 413 HapUiciiniis 415 Haploconiis aiignstus 410- liiioatHS 417 xiphodou 4->0 fulocouus 421 Pr<>to;;oni.i 424 I'roiojj;ouia idicilVr.i 424. siiliqnadrata 4'2G Aiiucoildn 427 Anacndon ursidcns 427 Pht-naciMlus 428 I'bi'iiacodii.s niiniuiius 434 prinucviis 4;i5. lii'iiiii'OiiiiH 4G3 vortniani 464 calceulatus 487 pucrccnsia 488 inacropfoniiiH 490 brachyiitcrnus 47 Hyrachyus princeps 661 sp 661 eximius 662 II C XVlll CONTENTS. TnE PiT.nro, Wasatch, and Bridger Faun^ — Continued. Mammalia : Pnge. Hyracbyus agrarius 675 implicatiis 676 TriplopodidiB 676 Triplopus 678 Triplopus oubitalis 679 amarorum 687 HyracodontulsB 691 Ehinocerido) 691 T,-»piri(liu 69:t Chalicotheriidao 694 Ectociou 690 Ectocion osbomiannm 696 PalsBOsyops 697 PaliBosyops vallidens 699 major 701 Iffividens 701 borealia 70;J Limnohyus 705 Limnohyus diaconus 70(> fontinalis 707 Lambdot helium 709 Lambdotberium brownianum 709 popoagicum 710 procyoninum 711 Macrancheniida 712 Menodontidie 713 PalcBotberiidte 7i:i Equidie 715 Artiodacty la 716 Omnivora 710 Pantolestca 717 Pantolestes chacensis , 719 bracbystomus 721 metsiacus 719 nnptns 720 etaagicns 724 longicaudns 725 secans 725 Addenda to Pakt First 727 Pisces 727 Pcrcomorphi 727 Plio|ilarcliU8 , 727 Plioplarcbat) whitoi 72ft scxspiuoaus 729 Rpptilia 730 Ophidia 730 Helagras 730 Holagras prisciforrais 730 Mammalia 732 Poly mastodon 732 Poly mastodon taoonsis 732 Cato|miiliH 7Xi Catopsalis pollnx 7;$4 Disaaciis 74 1 CONTENTS. xix Page. Supplement to Part First — The Amyzon Shales 742 Pisces 745 Halecomorphi 745 Amia 745 Amia scutata 745 dictyocephala 745 Nematognathl 747 Ehineastea 747 Ehineastes pectinatus 747 Plectospondyli 748 Amyzon 748 Amyzon men tale 749 commune 749 pandatum 750 fusiforme 751 Percomorpbi 752 Trichophanes 752 Trichophanes foliarum 753 hians 753 Aves 754 GraUiB 755 Charadrius 755 Charadrius sheppardianns 755 PART SECOND. The White River and John Day FACNiE 760 Reptilia 761 Testudinata 762 Testudo 762 Testndo cultratns 763 qnadratns 704 laticuneus 765 ligonius 766 amphithorax 767 Stylemys 769 Stylemy s nebrascensis 769 Lacertilia 770 Peltosaurus 771 Peltosaurus granulosus 773 Exostlnus 775 Exostinus serratua 776 Aciprion 776 Aciprion f ormosum 776 Diacium 777 Dlaciam quinquipedale 777 Platyrhacliis 777 Platyrhachis coloradoensis 778 unipedalis 779 rliambastes 779 Cremastosaurns 780 Cremastosaurus carinicollis 781 Ophidia 781 Aphelophis - 781 Aphelophis talpivoms 782 XX C02JTENTS. TiiK White Hivkr and John Pay Faun^ — Continued. Replilia: Pkge. Ogmophis 't?- Opnophis oreponensis 783 augiilatus 783 Calamagras 784 Calaiiiiijjras murivorus 784 Nearodioiiiii-iis 7'io Neiirodroniicus dorsalis 786 Maninialia 786 Marsdpiali:) 788 Perathprium 789 Perathcrium fiigax 794 tricuspis 796 huntii 796 scalare 797 niarginalo 798 altt-ruaiia 799 Bnnotheria 800 Creodoiita 800 Mesodoctes 801 Mesodectes caniciilus 805 Geolabis 807 Geolubis rhynchaeus 808 Insect ivora 808 Menotlicrinm 808 Menotherium lemurinum 809 Chiropttra 809 Doniiiiiia 810 Douinina gradata 810 crassigenis 811 Kodentia 812 Seiuromorplia 81G Scinrus 816 Scinras vortmani 816 relict us 817 balloviauus 818 Gymnoptychus 819 Gyiunoptychnsminutus 822 trilopLus 826 Meuiscomys 820 Meniscomys hippodiis 828 lioluphus 829 Meniscomys cavatus ' 830 niti-ns 832 Iscbyroinys 833 Iscbyromys typus 835 Castor 838 Castor pcninsiilatus 840 gradatns 844 Heliscoinyg 845 HcliBComys vet us 846 Myoniorpba 848 EnmyH 848 Euniys elogans 849 CONTENTS. XXI The White River and John Day Faun^— Continued. Page. Hesperomys So- Hesperomys nematodon 853 Paciculus ^53 Paciculus iusolitus 8.54 lockiugtonianus 854 Entoptycbus *555 Entoptychus planifrons 858 lambdoideus 860 minor 861 cavifrons 862 crassiramis 864 PleurolicuB 866 Pleurolicus sulcifrons 867 leptophrys S68 diplophysus 869 Lagomorplia 870 Palseolagus 870 Palffiolagus haydeni 875 trijdex 881 turgid us 882 LepuB 885 Lepus enniBianus 886 Cami vera 888 Amphicyon 894 Amphicy on vetus 894 hartshomianus 896 cuspigerus 893 Temnocyon 902 Temnocyon altigenis 903 wallovianus 905 coryphseus 906 Joseph! 912 Galecynus --• 914 Galecynus gregarius : 916 lippincottianus 9)9 geisniarianus 920 latidens 930 lemur 931 Enhydrocyon 935 Enhydrocyon stenocephalus 935 OUgobunis 939 Oligobunis crasslvultus 940 Hy senocy on 942 Hyisnocyon basilatus 942 sectorins 943 BtinsBlurus 946 Bunselorus lagophagus 946 osonim 947 NlmravidsB 947 Arcbfelurus 952 Arcbselurus debilis 9^3 Nimravus 963 Nimravns gompbodus 964 confert us 972 XXII CONTENTS. The White Riveu axd John Day Faunae— Continued. Reptattki Page. Dinictis 973 Dinictia cyclops 973 felinn 978 Bqnalidens 979 Pogonodon 981 Pogouodon platy copis 982 brachyops 987 Hoplophoneus 992 Hoplophoneus creodontis 993 cerebralis 997 strigidcns 1001 LIS!" OF -W O O D - C XJ X' S . Fio. 1, page 4. — Section west of tbe Galliiius Mountains, New Mexico, from Gallinos Creek to the Eocene Pl.Ttcau (Cope). Fig. 2, page 5. — Section along the east side of tbe Animas River, Colorado. (Hayden.) Fig. 3, page 6. — Section on the San .Juan Kiver, Colorado. (Hayden.) Fig. 4, page 8. — General section in the Yanipa district. (Hayden.) Fig. 5, page 13. — Scene in tbe Bad Lands of tbe White River formation in Nebraska. (Hayden.) Fig. 6, page 16. — Section in Eastern Colorado. (Cope.) Fig. Co, page 20. — Sand Hills, Northwestern Nebraska. (Hayden.) Fig. 7, page 2o7. — Distal extremity of tibia of Amhlijctonua tinotus Cope. Fig. 8, page 257. — Distal extremity of tibia of Oxytcna morsitans Cope. Fig. 9, page 257. — Portions of maxillary and mandibular bones of Ozyatna lupina Cope. Fig. 10, page 258. — Mandible of Oxi/cpna forcipala Cojje. Fig. 11, page 375. — Left anterior foot of Elephas africanua. Fig. 12, page 376. — Left anterior foot of I'henacodiis primcevm. Fig. 13, page 37G. — Right anterior foot of Hi/rax capcnsis. Fig. 14, page 376. — Right uiauns of Corijphoilon. Fig. 15, page 377. — Fore leg and foot of Iliiracolhenum renticolum. Fig. 16, page 378. — Left posterior foot of I'henacodus primccvua. Fig. 17, page 378. — Right jiosterior foot oi Hyrax cupcTitia. Fig. 18, page 379. — Posterior foot of Cori/phodon. Fig. 19, page 379. — Left pes of Elephas indiciis. Fig. 20, page 380. — Hiud foot of I'oHhiolherium lubiatum. Fig. 21, page 514. — Skull of Coryphodon clephantopus, displivying brain cavity. Fig. 22, page 515. — Right posterior foot of a siecies of Coryphodon. Fig. 23, page 522. — Profih; view of skull of Coryphodon clephantopus, from Now Mexico. Fig. 24, page 522. — Superior surface of skull of Coryphodon clephantopus. Fig. 2.5, page .533. — .Sknll of Coryphodon cUphanlopus. Fig. 2.'a, page 584. — Loxolophodon cornulus Cope; restoration. Fig. 26, p.age 599. — Uintalherium Icidianum ; from Osborn. Fig. 27, page .599. — Superior molar teeth of Uintalherium Icidianum; from Osboru. Fig. 28, page 599. — Loxolophodon spicrianum; from Osborn. Fig. 29, page .599. — Mandible of suppo.sed Loxolophodon; from O.sborn. Fio. 29n, page 599. — Inferior molars, external side; from Osborn. FlO. 30, page 599. — Inferior incisors of «up|i<)sed Aoxofiy/Ziorfoii, external and superior views; Osborn. Fig. 31, page 618. — Part of right maxill.iry bono of Jlejitodon singularis Cope. Fig. 32, page 789. — Skull of opossum (l)idelphys rirginiana). Fio. 34, page 939. — Oliyvbitnia cransirnllus Cojie ; part of skull wiHi lower jaw. Fio. 35, page 945. — JElurodon irheclirianus and Ai. hyacnoides Cope; jaws. Flo. 36, page 945. — JElurodon /•o'eus Lcidy ; skull with lower jaw nearly complete. Fig. 37, page 9.'>2. — .IrchnhiruK drhilis Cope; skull from below, showing foramina. Fig. 38, page 9HV.'. — I'ogonodon plalycopis Cope; skull, prolile. LETTER OF TRANSMISSION. January 1, 1879. Sir : I send herewith a report on the Tertiary Faunae of the United States as represented by collections made in various Territories and States west of the Mississippi River, embraced within the boundaries of your sur- vey. The explorations from which the collections have been derived cover portions of the States and Territories included between British America on the north, the western boundaries of Minnesota and Missouri on the east; the northern borders of the Indian Territory and Arizona, and the middle of New Mexico on the south; and the Sierra Nevada on the west. The amount of material which I have procured through these explorations is large, and is but partially represented in the following pages. I trust that you will find the results a useful contribution to the records of your Geo- logical Survey and to the science to which you have devoted your life ; and that you may find in this report some compensation for the arduous official duties which have recently withdrawn you to some degree from your chosen field of research. The preface gives an account of the methods pursued in conducting the investigation ; while the introduction embraces a general view of the stratigraphy of the Tertiary formations of the West. The system adopted is that proposed by yourself and Mr. King, with a few additions ; while several correlations with the horizons of the Old World are based on my own paleontological studies. The order of succession of faunae is observed in the following sections of the work; that is, part first, the Puerco, Wasatch, and Bridger formations ; part second, the White River and the John Day beds ; and part third, the Loup fork and Equus beds. The second half of the second part, the third part, and faunal lists, will constitute the succeed- ing volume. No. IV, of your series. I desire to express here the obligations under which I have been placed Xxiv LEITER OF TRANSMISSION. through the important aid and hospitahty rendered me by the following gentlemen : In 1872, at Fort Bridger, Wyo., I was assisted by Capt. K. 0. Clift, in command of the post, and by Lieutenant Rogers, quartermaster, and Dr. Joseph Corson, surgeon ; also by Judge W. Carter and Dr. J. V. Carter. In Montana, in 1S7G, I received important aid from General E. 0. C. Ord, commanding the Department of the Missouri, and Major Ilges, in command at Fort Benton; and in my explorations in Washington Temtorj-, in 1879, I was under obligations to Dr. George H. Sternberg, U. S. A.* In 1880-81 the military authorities at Fort "Washakie, Wyo., rendered me much assist- ance, particularly Col. J. W. Mason, commanding, and Dr. W. H. Corbu- Bier, post surgeon.* I have received important aid from Professor Baird, of the Smithsonian Institution, and from Professor Condon, of Eugene City, Oreg. I wish here to place on record the names of my assistants, who have contributed greatly to the success of my expeditions, viz : William G. Shedd, Charles H. Sternberg, Jacob Boll, J. C. Isaac, Russell S. Hill, Frank Hazard, Jacob L. Wortman, and D. Baldwin. T have been also favored by special rates by the general officers of the Union and Central Pacific, and Pennsylvania Railroad companies. I wish here to express my thanks to Messrs. Kimball and Stebbins of the Union, and Governor Stanford of the Central Pacifies, and to Presidents Scott and Roberts of the Pennsylvania Railroad. The lithographic work of Messrs. T. Sinclair & Son maintains the well-known reputation of their house, and will prove satisfactory to students generally. I am, witli respect, E. D. COPE, Paleontologid, United States Geological Survey of the Territories. Dr. F. V. Hayden, Director of the United Stales Geological and Geographical Survey of the Territories. •In my explorations of foriiifttioim otlirr tliiin those treatwl of in tbi« volume, I have been assiated oy other gentlemen, gouoriiUy ollicers of the Army, to whom I will refer in the ft])]>n>i)riate place. PREFACE. 1. Sources of Collections. — The localities which yielded the fossils described in the following pages are the following : In 1872 I conducted an exploring party in Southwestern Wyoming. I left Fort Bridger July 19, and followed the road to Cottonwood Creek, southeast eighteen miles, whence we made our first excursions into the bad lands. After this our route laid along Cottonwood Ci'eek to Smith's Fork of Green River, thence along Black's Fork, and thence to Green River City. We then followed Bitter Creek to Black Buttes, and, leaving the line of the Union Pacific Railroad, ti-aveled south toward the headwaters of the Ver- million. Before reaching this point we explored the Mammoth Buttes, which form the water-shed between South Bitter Creek and Vermillion, and ex- amined the bad lands of the Washakie Ba.sin carefully. In reaching this point we crossed a portion of the Cretaceous formation, and I took especial pains to determine the relations of the strata at these points. We returned from this region and struck Green River seventeen miles above Green River City. We proceeded northward to the mouth of La- barge Creek, and, returning a short distance, ascended Fontanelle Creek to near its source in the outlying ranges of the Ham's Fork Mountains. The relation between the lake-deposits and the older strata here claimed special attention. We then descended Ham's Fork to the Union Pacific Railroad and returned to Fort Bridger. Special expeditions were made to the region round Evanston, and to Elko, Nev., with gratifying success. We obtained, in round numbers, one hundred species of vertebrated animals of the Eocene period, of which about sixty were new to science. We obtained material for the addition of two orders of mammals to those XXVI I'lIKFACE. previously represented in this fauna in the United States, viz, the Mcsodonta and Amhlypoda, the latter in several types of remarkable interest. In 1873 I fitted out an expedition at Greeley, Colo., and traversed the Plains eastward toward Julesburg as far as the eastern branches of the Cedar or Horse Tail Creek. Our route was parallel to the line of the so-called Chalk Bluffs, which extend from west to east, forming a break in the southern slope of the surface of the country from the dividing of the waters of the North and South Platte. It consists of the Loup Fork sandstones resting on a basis of the upper beds of the White River formation. The countr}- be- tween the foot of the bluffs and the South Platte River is composed in its northern part (if the White River tornialinii, Avl.icli jiresents exposures at various points, and neai-er the river consists of the Laramie formation. On this part of the expedition 1 obtained seventy-five species fnnn the White River beds, and twenty-one from the Loup Fork. We then turned to the southwest, crossing the South Platte, and moved up the valley of Bijou Creek towards the highlands of Colorado east of the mountains, known as the Colorado divide. On this part of the expedition, which was in charge of William G. Shedd, a number of interesting reptiles of the Laramie period were discovered. The party then entered the South Park and obtained a fine collection of the fishes of the Florissant shales During this time I had made an excursion to Fort Bridger, Wyo., and had supplemented the collections of the previous year. In 187 ^ I sent my assistant, J. C. Isaac, to Montana for the purpose of examining the valley of Deep River for the fossiliferous deposits previously reported to exist there by Captain Ludlow, United States Engineers, and examined by Messrs. Dana and Grinnell of his party. The results were satisfactory, a considerable number of fine specimens having been secured. Mr. Isaac then passed southeastward into W3'oming, and explored the White River beds of the southern parts of that Territory and the adjacent bor- ders of Wyoming. The same year I employed Charles II. Sternberg to conduct an explora- tion of the Cretaceous and Tertiary formations of Kansas. After a success- ful search I sent Mr. Sternberg to Oregon, and Russell S. Hill took charge of the expedition. Under his management an excellent collection of the PEEFACE. XXvii Mammalia and Reptilia of tlie Loup Fork formation of Northern Kansas was made, Mr. Hill discovering several new species of Mastodon, rhinoce- roses, tortoises, &c. The Tertiary formations explored in 1878 were the John Day, Loup Fork, and Equus beds, of Oregon. These were examined by Mr. C. H. Sternberg, who received important aid from his brother, Dr. George M. Sternberg, U. S. A. The John Day formation was chiefly examined on the John Day's River, and the Loup Fork beds at various points in the same region. These yielded about fifty species, many of them ]-epresented by specimens in an admirable state of preservation. The Equus beds were examined both in Washington and Oregon; in the former near to Fort Walla Walla, and in the latter in the desert east of the Sierra Nevada. The basin of an ancient lake, originally discovered by Governor Whit- aker, of Oregon, was found to be strewn with the bones of llamas, horses, elephants, sloths, and smaller mammals, with birds; and all were collected by Ml-. Sternberg and safely forwarded to Philadelphia. I examined this locality myself in 1879, and obtained further remains of extinct and recent species of mammalia found mingled with numerous worked flints. In 1879 Mr. J. L. Wortman took charge of m}^ party exploring in Oregon, and made extensive and valuable collections of the fossils of the John Day and Loup Fork beds of the eastern part of that State. In 1880 Mr. Wortman explored the deposits of the Idaho Pliocene lake of the Snake .River Valley, and made a valuable collection.* The same year he examined the Eocene beds of the Wind River Basin previously discovered by Dr. Hayden, and sent east forty-five species of vertebrata, of which twenty-four were new to science. In the following year Mr. Wortman pushed his explorations northwards, and discovered that the basin through which the lower part of the Big Horn River flows is filled with deposits of Wasatch Eocene age. These he examined for vertebrate . remains, and succeeded in obtaining sixty-five species, of which twenty- seven were previouslv unknown. Most important additions to our knowledge of the structure of various types were made, owing to the i-emarkably perfect condition of some of the specimens. •Proceedings Academy, Philadelphia, 1883, p. 153. XXVllI PREFACE. In 1881 I employed Mr. D. Baldwin to colk-tt fossils in the Puerco fomiation of New Mexico, which I discovered in 1874. Mr. Baldwin's suc- cess has had a very important bearing on the science of paleontology. He has obtained more than sixty species from that formation, iie:uly nil of wliirU were new to science. The expeditions have not been conducted without risks. My explora- tion in Western Kansas was made during a state of hostility of the Chey- enne Indians, and in a region where they were constantly committing mui- ders and depredations. During my expedition of 1872 I was abandoned by some of my party, who robbed me of mules and provisions, and placed me in some bodily peril. My expedition of 1873 was in the Cheyenne country, and constant vigilance was necessary. The year following my visit the whites were driven from the region, or murdered, by the Indians of that tribe. In 1876 I entered the Sioux country with my party on the Upper Missouri while the Indians were engaged with General Custer on the Little Big Horn and the Rosebud. My guide and camp tender abandoned me, and before leaving the country we passed a point a day's ride from Sitting Bull's camp on the Dry Fork of the Missouri. Mr. Sternberg's expedition of 1877 was interrupted by the Bannock war, and both himself and Mr. Wortman were compelled to leave their camp and outfit in the field and fly to a place of safety on their horses. In attempting to cross the Wind River in 1880 Mr. Wortman's horses and wagon were carried a\va\' li\ the current and the greater part of his baggage and provisions lost. Ilis exploration of 1881 was conducted under circumstances of nnuli risk from the absence of water. All the water necessary to the existence of his ani- mals and men had to be carried a distance of twenty miles on the backs of mules It is evident that an enthusiastic devotion to science has actuated these explorers of our western wilderness, financial considerations having been but a secondary inducement. And I wish to remark that the courage and regardlessness of physical comfort displayed liy thr gentlemen above refeired to in the pursuit of the idea of progress, are qualities of which their country may be proud, and are worthy of the highest commendation and of imitation in every field. PEEFACE. XXIX I have also received miscellaneous collections from G. W. Marnock, of Texas, from the late Tertiary formation of the southern part of that State, and from various persons in Nebraska, Dakota, &c. A few small collections received through the office of the United States Geological Survey of the Territories are mentioned in the proper places. 2. Mode of Preservation of Collections. — Since the value of deter- minations in vertebrate paleontology depends greatly on the condition of the collections, I give here some explanation of the methods I have employed in this direction. Prior to the publication of the descriptions of Elasmosaurus and various species of Pyfhonomorplia, from Kansas, in 1869-70, complete skeletons from the western deposits were unknown in eastern collections, or, if existing the fragments of different animals were so commingled as to be unavailable for purposes of determination. As it is self-evident that the science can make little progress without the discovery of entire skeletons, I have made every effort to secure them, commencing with my exploration of the Cre- taceous beds of Kansas in 1871. In the field entire skeletons are not rare, as' animals have often been entombed in soft deposits more or less uninjured. To obtain them in an entire condition, however, requires an unusual conjunction of circumstances The skeleton must be visible, but not so ftir exposed to the weather as to have suffered injurv from frost and rain, and it must not penetrate a hard matrix so deeply as to be inaccessible. As is the matrix, so is usually the fossil ; friable fossils belong to a soft rock, and hard ones to a hard rock. The exceptions to this rule are fossils found in dry sand, which are hard. In collecting, the first precaution to be observed, is to trace weathered fragments to their proper source in the adjacent deposit. This will of course be done, if at all, by following up the line of descent, either of escarpment or of water wash. If the remainder of the skeleton be found in place, the true correlation of the fragments will soon be discovered. The difficulty of extricating bones from the inatiix depends on the hardness or softness of the latter. The most favorable condition is an intermediate one, neither hard nor soft. The chalk of the Niobrara Cretaceous presents the most favorable conditions; next in order the matrix of the Bridger and ^ V V XXX PKEFACE. John Day formations preserves the bones best for extrication. The Wliite River formation of the Plains is only inferior in being a little softer, while the material of the Laramie formation varies between too great hardness or too great softness. The same difficulty, though in a less degree, is met with in the Loup Fork beds, softness predominating, while the least favorable of all for the preservation of fossils are the Puerco and Wasatch formations, where concretionar}' hardness prevails. In all of my expeditions great care has been exercised in preserving the relations in which the fossils have been found by placing marks on the same and by preserving notes and drawings made on the ground. These precautions are of course absolutely necessary to secure accuracy in the reference of the various fragments into which a skeleton is often broken. On the arrival of the collections in Philadelphia the labels on the packages insure their correct classification, and the work of reuniting the broken pieces commences. In many cases crania, bones, and skeletons having been taken out in a moi'e or less entire condition, inclosed in rock masses, much time is consumed in dressing them out with mallet and chisel. The amount of labor required for the preparation of the material of the present report alone, is easily seen to have been very great. I here refer to the skill of my assistant, Mr. Jacob Geisman, to whom the excellent character of this work is largely due. 3. Publication of Results. — The media of publication of the results of the investigations embraced in the present volume have been the fol- lowing : 1. Bulletin of the United States Geological and Geographical Survey of the Territories, F. V. Hayden in charge, Washington. 2. Annual Reports of the United States Geological and Geographical Survey of the Territories, Washington. 3. Proceedings of the American Philosophical Society, Philadelphia. 4. Proceedings of the Academy of Natural Sciences, Philadelphia. 5. Paleontological Bulletins. By E. D. Cope, Philadelphia. The last-named series consists in large part of rei)rints of papers which have appeared in the serials, Nos. 3 and 4; principally in No. 3. These reprints have averaged 200 copies each, but have sometimes amounted to PEEFACE. XXxi 300 copies ; in a few cases but 100 copies were issued. They have mostly- appeared in advance of the number of the serial which contains them, owing to the long intervals at which the latter were or are issued. Thus the Pro- ceedings of the American Philosophical Society were, up to a recent date, published but once in six months, and those of the Academy of Natural Sciences three times in the year. In some instances the Paleontological Bulletins have not appeared in any serial. In the earlier part of my inves- tigations the reading of the proofs of these and other papers was sometimes intrusted to other persons, owing to my absence from Philadelphia while conducting explorations. These persons at times allowed important typo- graphical errors to escape them, and in a few instances introduced alterations of the text, for which I wish to disclaim responsibility. This experience led me to avoid such confidence thereafter, so far as practicable. The literature of the Paleontology is given under the head of the separate divisions of the subject in which it appropriately falls. 4. Rules of Nomenclature. — I have adhered to the laAv of priority, as generally understood, in the use of names both in the biological and stratigraijhical aspects of the subject. I take this opportunity of noting what appears to have been at times forgotten by a few students of verte- brate paleontology — although fully recognized by biologists generally — that a name, unaccompanied by a definition or a precise reference to an existing definition, has no status in scientific nomenclature. A word so introduced is meaningless, and cannot be used, because that which it represents is unknown. Thus, names of classes and orders which refer only to popular definitions, such as "flesh-eaters," "insect-eaters," "whales," "worms," &c., have no scientific existence. These divisions of recent animals having been, however, by this time, well established by true analysis, the names pro- posed for extinct groups which are now being discovei'ed claim our attention.* The progress of paleontology has been retarded by the publi- cation of numerous names, supposed to refer to family and generic divisions, which are not accompanied by descriptions or by any statement of the reasons why their author has created them. Characters of the species desci'ibed *See Proceedings Americjm Pliilos. Society, 1873, p. 73. Report U. S. Geol. Survey Terrs., 4to, II, p. 113. Report of Lieut. G. M. Wheeler, U. S. Geogr. Surv. W. of 100 Mer., IV, Pt. II, p. 148. XXXll PREFACE. under the proposed generic name are usually given, and in some instances characters which really belong to the definition of the genus to which it belongs may be found mingled with them. In these cases it is left for the reader to discover these characters. Should he do so, he becomes the real discoverer of the genus, and as such is entitled to name it. The pub- lication of names in the manner objected to is, from every point of view, pernicious, and is very properlj' forbidden by well-known rules. It mat- ters not if it be ascertained at a subsequent date, and by some circumstan- tial evidence, what the author of such names referred to as to species and specimens. Such information cannot habilitate a nomen nudum ; nor is such circumstantial evidence accessible to students generally, especially to those who live at some distance from the locality whence it may be obtained. I now append the most important rules of nomenclature, as adopted by a majority — in most instances, a very large majority — of forty-five of the leading biologists of North America. They are included in the report of a Committee of the American Association for the Advancement of Science, appointed in 1876, of which Capt. W. S. Dall, U. S. N., was chairman.* 1. The reading of a paper before a scientific body does not constitute a publication of the descriptions or names of animals or plants contained therein. 2. A name applied to a group of species without a specification of any character possessed by them in connnon (that is, without any so-called generic diagnosis or description), is not entitled to recognition as an estab- lished generic name by subsequent authors. 3. A generic name applied to a single (then or previously) described species without a generic diagnosis or description of any kind, is not entitled to recognition as above, by subsequent authors. 4. A subsequent author shall not lie permitted in revising a composite genus (of which no type was specified when it was described) to name as its type a species not included by the original author of the genus in that latter author's list of sj)ecies given when the genus was originall} described. 5. \Yhen an old genus without a specified type has been subdivided by a subsequent author, and one of the old species is retained and specified * See American Naturalist, August, 1678. PEEFACE. - XXxiii to be the type of the restricted genus bearing the old name, it is not com- petent for a third author to discard this and select another of the original species as a type, when by so doing changes are necessitated in nomenclature. 6. When a generic name has lapsed from sufficient cause into synonymy, it need not be thenceforth entirely rejected from nomenclature, and may still be applicable to any new and valid genus. The earlier pages of this volume were printed between two and three years prior to the greater part of it, hence some of the earlier statements will be found to be modified in the more detailed discussions which follow. One such point is the distinction which should be maintained between the John Day and White River epochs; another point is the great distinction which should be recognized to exist between the Puerco and later Eocene periods. The faunae of the Puerco and Wasatch epochs are as diverse from each other as are those of the Bridger and White River. Some inequalities in the text, and the intercalation of numerous plates which carry letters attached to their numbers must be explained. These peculiarities are due to the fact that the discovery of the Puerco fauna was made after the first pages of the volume had been struck off, and the greater number of the plates had been numbered and printed. The present volume includes the vertebrata of the Eocene and of the Lower Miocene, less the Ungulata. There are described three hundred and forty-nine species, of which I have been the discoverer of all except thirty- two. They are referred to one hundred and twent3^-five genera. The most important results which have accrued to paleontology through the researches here set forth, are the following: (1.) The discovery of the Laramie genus Champsosaurus in Ter- tiary beds. (2.) The discovery of Plagiaulacidce, in Tertiary beds. (3.) The discovery of the characters of five families and many genera and species of the Creodonta. (4.) The discovery of the characters of the Periptychidoe and its included genera; and (5.) Of the Meniscotheriidce ; and (6.) Of the Phenacodontidce and its genera. Ill (; XXXI V PREFACE. (7.) The discovery of the characters of the suborder of Condylarthra and of the phylogenetic results of the same. (8.) The discovery of the characters of the Pantolambdidce ; and (9.) Of the suborder Taligrada and its implications in phylogeny. (10.) The discovery of the Anaptomorphidendic- g- ular walls constituted a great impediment to our prog- K ress. During- the days of my examination of the region '% heavy showers of rain fell, filling the arroyos with rush- § ing torrents, and displaying a peculiar character of this > marl when wet. It became slippery, resembling soap in g consistence, so that the hills were climbed with difficulty, - and on the levels the horses' feet sank at every step. The ^ material is so easily transported that the drainage chan- | nels are cut to a great depth, and the Puerco Eiver '•^ becomes the receptacle of great quantities of slimy look- S? ing mud. Its unctuous appearance resembles strongly ? soft soap, hence the name Puerco, greasy These soft § marls cover a belt of some miles in width, and continue at the foot of another line of sandstone bluffs, which bound the immediate valley of the Puerco to a point eighteen miles below Nacimiento. ,s'fnr.52, 7,I0U'. n "Anuual Report U. S. Geol. Surv. Terrs., 1875, p. 189. t Annual Report of Chief of Engineers, 1875, p. t Loc. cit, 247. Appendix L L. VERTEBRATA OF THE TERTIARY, ^^ T1m» PiitTco marls liavt- tlii-ir jiriiK-ipal devtloitnieut at this locality. I exam- ined them throughout the forty miles of outcrop which I observed for fossil re- mains, but succeeded in finding nothing but fossil wood. This is abundant in the region of the Galliuas, and includes silicilied fiagments of dicotyledonous and palm trees. On the Puerco, portions of trunks and limbs are strewn on the hills and ravines; in some localities the mass of fragments indicating the place where some large tree had broken up. At one point east of the river I found the stump of a dicotyledonous tree which measured 5 feet in ^ I > diameter. The fauna of this formation is diftereut from that of the other Eocenes in the presence of a saurian. Cha»ip80saun(.s. which is characteristic of the Laramie Cretaceous, and of marsupial Mammals {Ptilo- ^ ^ '^ 'liii and Catnjmilis) which are remnants of a type = -■ -fi known otherwise from the Jurassic. Characteristic x i -^ genera are Catathlceus, a many-toed omnivore, FnU- Z t = tacotherinm, a gnawing TiUodont, and various flesh- = ■? s eaters with primitive teeth. Coryphodon is, so far, " o ^ unknown. 3 '•^' a t K o 1:2 THE WASATCH. 2 3D o The Wasatch Group is the lowest of a series of "o v. I these fresh-water Tertiaiy groups, all of which are inti- c B"? mately connected, not only by an evident continuity of > >• o sedimentation throughout, but also by the passage of a "I •= H portion of the molluscan species from one group up into 2 ;^ I the next above. Not only were those three groups, = f i. aggregating more than a mile in thickness, evidently to £ ^ produced by uninterrupted sedimentation, but it seems ^ .| i e()ually evident that it was likewise uninterrui»ted lie- § I T tween the Laramie and Wasatch epochs, although there f J f was then a change from brackish to fresh waters, and "^ ^f a consetpient change of all the species of invertebrates 1 - J then inhabiting those waters. "■ I e In his annual rejtort for 1870, Dr. Ilayden pro- 2 S. posed the name *' Wasatch Group " for a series of strata " ''" that are extensively developed in Southern Wyoming J and adjacent parts of Utah and Colorado. I regard s the series of strata to which Mr. King lias given the ^ name "Vermilion Creek Group," and Professor Powell _■ that of "Bitter Creek Grouj)," as geologically equiva- lent with the Wasatch Grf)ui) of Dr. Ilayden, and 1 therefore use that name iu this report in accordance with tlie recognized rule iu such cases. WASATCH EPOCH. 7 The preceding remarks I have quoted from the report of Dr. C. A. White to Dr. Hayden,* as expressive of the position of this important for- mation. In hthological character, the Wasatch consists of a mixed arenaceo- calcareous marl, alternating with beds of white or rusty sandstone. The more massive beds of sandstone are in New Mexico, Colorado, and Wyo- ming, at the base of the formation. The mai-ls readily weather into the fantastic forms and canyon labyrinths of bad-land scenery. The marls often contain concretionary masses of a highly silicious limestone, which cover the banks and slopes of the bluffs with thousands of angular frag- ments. It is' characteristic of this formation that the marls contain brightly colored, usually red, strata ; and in many localities the colors are various, giving the escarpments a brilliantly banded appearance. Petrographically, this formation has two divisions, the Wasatch proper and the Green Eiver beds ; the latter name having sometimes been given to the entire formation as well as the former. Dr. White thus describes it:t Eesting immediately and conformably upon the Wasatch are the strata of the Green Eiver Group. Although intimately connected with the former by continuous sedimentation and specific identity of molluscan species, they differ considerably from those of that group in general aspect, and in composition also. The group is, Uthologi- cally, at least, separable into two divisions, but they are not regarded as severally of co-ordinate value with the other recognized Tertiary groups. The lower division consists mainly of silicious and sandy shales and laminated and thin-bedded sandstones, with, in some places, especially in the western part of this district, frequent layers of hard, dark-colored carbonaceous shales. In some places the strata are also quite calcareous, occasional layers being nearly pure, compact, finely-laminated limestone. Others of the calcareous layers are sometimes oolitic in textui-e. The general aspect of the strata, as seen exposed at a distance, is light gray. The upper division consists mainly of sandstones that are coarser, as well as less thinly and distinctly bedded, than those of the lower division. In some parts it is shaly and in others carbonaceous. Much of its sandstone is ferruginous in aspect, instead of having the gi'ay tint that the lower division has. Sometimes certain beds of its sandstones are eailhy aud easily disintegi-ated, often lea\dng, weathered out of the mass, spherical concretions of hard sandstone that vary in size from a fraction of an inch to two or three feet in diameter. Other beds sometimes present buttress-like masses in the brow of bluifs, which form conspicuous and somewhat remarkable fea- tures in the landscape. Such features are very characteristic of this division in the bluifs of Green Eiver, in the vicinity of Green Eiver City, Wyo., and, to a less extent, they also appear in the bluifs which border the canon and valley of White Eiver, in the southwest portion of this district. •Aiiuunl Report, 1876 (1H78), p. 35. t Annual Report U. S. Geol. Surv. Terrs., 1876 (1878), p. 35. 8 VEKTEBRATA OF THE TERTIARY. The invertebrate fossils which this group affords are similar to those that are found in the fresh-water portion of the Wasatch Group, some of the species being TTpper tarbaniferan* ^ri^?fr..fi*?r?^*. /s l Y ii i i ' i i' iyi l'i f T T T i ' i ,i'i i !M'i,i' i i:i/(i /vi ;i.' ■;i;i; z^:;^^;^^^^ Fio. 4. — General Beclion in tho Yniniia diHtrict. White in Annual Report United States Geological Survey Territories, 187G. i<1fntical, niid iiidicat*' a jmrcly frcsliwator ooiuHtioii tlironplumt. They are almost wholly iiutllnscaii, and belong to the branchitcroiiH genera Vnw,Vivij>aru«, and Gonio- WASATCH EPOCH. 9 basis, besides several genera of pulmonate gastropods, including both thelimnophile and geophile divisions. The Green Eiver Group has become somewhat noted for the fossil fishes that have been discovered in its strata in Wyoming, and, like the Wasatch Group, it has at various localities also furnished considerable collections of fossil vertebrates and plants. Of the few vertebrate fossils known from the Green River division, some are identical with those of the Wasatch, while at least one genus of fishes is common to the Bridger. The Wasatch beds proper are much more widely distributed than those of the Green River. They appear first in the south in Northwestern New Mexico, and extend thence into the adjacent parts of Colorado. They are exposed over extensive areas of Colorado west of the Rocky Mountains, and reappear in Southwestern Wyoming. They extend along the western portion of the Green River Valley, whose northern portion they entirely occupy. On the eastern side of the Wind River Mountains it has, accord- ing to Hayden, an exposure of from one to five miles in width for a distance of one hundred miles, from the source of the Wind River to the Sweet Water River. North of this point it fills the extensive basin of the Big Horn River to the borders of Montana. It does not occur east of the Rocky Mountain range. The thicknesses given by geologists are the following: Northwestern New Mexico (Cope). Feet. Ked-striped marls 1,500 Eeddishbrown sandstone 1,000 2,500 Bio San Juan, Colorado (Holmes). Coarse yellowish sandstones, alternating with variegated marls 1,200 White and Tampa Reservations (Endlich and White). Chiefly yellow and reddish sandstones, alternating with shales 1,600 Bear Eiver, Wyoming (Hayden). Eed-bauded marls 700 Sandstones and shales 800 1,500 Wind River Valley (Hayden). Variegated marls and sandstones 5,000 The Green River division of the Wasatch is much less extensively distributed than the Wasatch proper. Its exposures are confined to the 10 VEETEBRATA OF THE TERTIAEY. valley of Green River, particularly the regions between its atSuents both north and south of the Uinta Mountains. In the Bridger Basin it forms a ^Nnde rim around the Bridger formation, and is especially developed on Fontiinelle Creek, and on Bitter Creek, and the region to the south of it. I here found its thickness to be 1,200 feet.* Farther south, in Western Colo- rado, near the Yampa River, Dr. "White gives its depth at 1,400 feetf Farther south, in Western Colorado, Dr. A. C. PealeJ gives the united thickness of this formation and the Wasatch at 7,670 feet; but how much of this is to be refen-ed to the Green River proper we are not informed. It does not appear to exist on the San Juan, according to Endlich and Holmes, and I did not find it in New Mexico. According to King, the deposits of the Green River formation rest un conformably on those of the Wasatch. § He also believes that it has a considerable extent west of the Wasatch Mountains, over parts of Utah and Nevada. Under the head of the Bridger formation I show that the paleon- tological evidence is opposed to the identification of these "Amyzon" beds with the Green River, and that they are probably of later origin. There is, however, a series of calcareous and silico-calcareous beds in Central Utah, in Sevier and San Pete Counties, which contain the remains of differ- ent species of vertebrates from those which have been derived fi'om either the Green River or Amyzon beds. These are Crocodilus sp., Clastes sp., and a fish provisionally referred to Priscacara, under the name of P. testudinaria. There is nothing to determine to which of the Eocenes this formation should be referred, but it is tolerably ceiiain that it is to be distinguished from the Amyzon beds. In its petrographic characters it is most like the Green River. II The writer first refen-ed the Wasatch to the Eocene division of the Tertiary, it having been previously regarded as Miocene. (Proceedings American Philosophical Society, February, 1872.) The vertebrate fauna of the Wasatch is rich, and presents many pecu- • Annual H.port U. S. Gool. Snr\-., 18T3, pp. 436, 43!}. t Annual K.-port U. S. Gfol. Suit., 1870, p. 30. t Annual Ri-porl li^4, p. l."*. $U. S. SnrvfV of thr Foitipth Parallel, i, p. 377. II See American Naturnlist, April, lri@0. BRIDGEE EPOCH. 11 liarities. It is nearly identical with that of the Suessonian of Western Europe, which is at the base of the Eocene series. The fullest account of it is that which I have given in the Report of Captain Wheeler of Explora- tions and Surveys West of the 100th Meridian, vol. IV. THE BRIDGER. This is one of the more important of the groups among those that, in Western Iforth America, are referred to the Tertiary i^eriod, especially as regards the vertebrate remains that have been obtained from its strata. It is most fully and characteristicaUy developed in the region known as the Green River basia, north of the Uinta Mount- ains, only the southeastern portion of the formation, so far as it is now known, extend- ing into Northwestern Colorado. In its typical localities it is found resting conform- ably upon the Green Eiver Group, into which it passes without a distinct plane of demarkation among the strata. Irs molluscan fossil remains correspond closely with those of the Green River Group, some of the species being common to both, all indicating a purely fresh con- dition of the waters in which the strata of both groups were deposited. At the typical localities the group is composed in great part of soft, variegated, b^d-laud sandstones, a peculiar greenish color often predominating over the others, which are reddish, pur- ple, bluish, and gray. Limestone strata, marly and clayey beds, and cherty layers are not uncommon, and grits and gravelly layers sometimes occur. To the above general remarks of Dr. C. A. White I add, that the ma- terial of this formation consists of indurated clays more or less arenaceous, which display various degrees of hardness. The harder beds are, however, thin, and the intervening strata yield readily to meteoric influences. They are frequently quite arenaceous, and rather thin beds of conglomerate are not uncommon. The colors that predominate are greenish-gi-ay and brownish-green, with frequent ash-colored beds. The peculiar condition of hardness of most of the strata render it one of the formations which most generally present the bad-land scenery ; it permits the erosive action of the elements without general breaking down, great numbers of frag- ments of the strata remaining in spaces between the lines of erosive action. The result is the extraordinary scenery of Black's Fork, Church Buttes, and Mammoth Buttes, of which mention will be made in the section of this volume especially treating of the Bridger foimation. The distribution of the Bridger formation is limited, and is, so far as I am aware, restricted to three areas, whose mutual connection is as yet un- certain. Its principal mass is in the Bridger basin, which extends from the 12 VERTEBRATA OF THE TERTIARY. northern base of the Uinta Mountains to the latitude of the mouth of the Big Sandy River nortliward. In this area it reaches a depth, according- to King,* of 2,000 or 2,500 feet. A second district is also in Wyoming, and lies east of Green River between Bitter Creek and the northern boundary of Colorado, in what is called by King the Washakie basin. The depth of the formation there reaches 1,200 feetf The third region is in Western Colorado, where it loses much of its importance. Dr. C. A. White found it only 100 feet in thickness near the White River. J Dr. Peale found it near the Gunnison River, as he discovered vertebrae of Pap- pichthys, a genus which belongs to this horizon only ; but he did not dis- tinguish it from the underlying formations, so that I do not know its thick- ness at that point. South of this locality it is unknown. As already pointed out, this period is especially characterized by a peculiar and rich vertebrate fauna. THE XJINTA. Resting directly, but by unconformity of sequence, upon all the Tertiary and Cre- taceous groups in the region surrounding the eastern end of the Uinta ^lountaia range is another Tertiary group, that has received the name of " Uinta Group" from Mr. King, and "Brown's Park Group" from Major Powell. § It is possible that this group was deposited continuously, at least in part, with the Bridger Group, but at the places where the junction between the two groups has been seen in this region there is an evident unconformity, both by displacement and erosion. The group consists of fine and coarse sandstones, with frequent layers of gravel, and occasionally both cherty and calcareous layers occur. The sandstones are some- times firm and regularly bedded, and sometimes soft and partaking of the character of bad-land material. The color varies from gray to dull reddish-brown, the former pre- vailing north of the Uinta Mountains and the latter south of them. The only invertebrate fossils that are kuown to have been discovered in the strata of this group are some specimens of a Pliysa, very like a recent species. Therefore, invertebrate paleontologj' has fimiished no evidence of its assumed Tertiary age and lacustrine conditions of its deposition. Its fresh-water origin, however, seems unques- tionable, because of its intra-continental position, its limited extent, and the fact that none but freshwater deposits are known in this part of the continent that are of later date than the close of the Laramie period. To these remarks of Dr. White I add, that several species of vertebrata have been obtained from this formation by Professor Marsh, who has deter- • Gool. Explor. Fortiith Pnrallpl, ii, p. 245. t Aiiniml Hi-iiort U.S.Geol. Siirv. Ivm., 1873 (1874), pp. 436-437. I Anniiiil R<>port, 187(), p. :it). ♦ Anuoal Report U. 8. Geol. Siir>-. Terra., 1874, pp. 157, 158. WHITE EIVER EPOCH. 13 xnined from it a few genera of Tertiary and Upper Eocene character. Such are of Mesodonta, the genus Hyopsodus, and of Ungulata, the Perisso- dactyle form Amynodon. i THE WHITE RIVER. I The materials of t which the beds of this & formation are composed f in their eastern division, T are calcai-eous clays and ^ marls, alternating with a ? few unimportant strata ^ of light-colored sand- « stone. They are white i and gray, with occa- o- sionally a pink and red, g- and sometimes greenish S. tinges. The beds of the ? western deposit in Ore- i gon consist of a more ^ or less indurated mud, g which is, according to o King, of trachytic ori- a gin, which is rarely hard, 1 and frequently rather soft. Its predominating color is light green, but is frequently olive and light brown. The depth of the formation on the 14 VERTERRATA OF THE TERTIARY. White Kiver of Nebraska is, according to Hayden,* about 150 feet; and on Crow Creek, Colorado, according to King,t 300 feet. Sixty miles east of Crow Creek I estimate its thickness as somewhat greater. The Truckee beds of Oregon have, according to Marsh, a depth of from 3,000 to 4,000 feet, and King estimates the deposit exposed in the Hawsoh Mountains, Nevada, at 2,300 feet.J An extensive deposit exposed in the region of the Cajon Pass, Southern California, is suspected by King to belong to the same horizon. The followinjr section by Dr. Havden exhibits the strata of both this formation and the overlying Loup Fork epoch, as displayed on the White River, Nebraska. The bed marked E, and those above it, belong to the last-named formation. Sl'BDIVnSIONS. Localities. li .s-g 1^ g m g i 03 o u n Gr.ay and grceuish-gr.iv sandstone, varying from a very fine compact structure to a conglomerate. Bijon HiUs, Medicine Hills, Eagle Kest Hills. 9 d a Yellowish-gray grit, passing down into a yellow and light-yellow .argillo-calcareous marl, with nu- merous calcireons concretions and much crystalline material, like sulphate of baryta. Fossils: Hip- potherium, Protohippus, .Steneotiber, &c. Bijou Hills, Medicine Hills, Eagle Nest Hills, and numerous localitiesou south side of White River, also at the head of Teton River. 1 1^' Q (S n Grayish and light-gray rather coarse-grained sandstone, with much sulphate of alumina? dis- seminated throngh it. Along Wliite River Val- ley, on the south side. i 1 Yellowish and flesh-colored indurated argillo-cal- careous bed, with tough argillo-calcareons concre- tions, containing " Testudo, Hippotherium, Steneo- fiber, Oreodon. Rhinoceros," &c. Seen along the White River Valley, on the south side. 1 8 d Yellow and light-yellow calcareous marl, with argillo-calcareous concretions and slabs of silicious limestone, containing well-preserved fresh-water shells. On the south side of White River. Seen in its greatest thickncssatPinao's Spring. 1 o * Proceedings Academy Philada., 18.")", p. l-'iS. tReportof Geol. Survey of 40tli rarnllel, i, 410. JL. c, p. 423; 1. c., p. 415. WHITE EIVER EPOCH. 15 Subdivisions. Localities. |i II i t-H 8 Light-gray silicious grit, sometimes forming a compact fine-grained sandstone. Seen on both sides of White River. Also at Ash Grove Spring. A reddish flesh-colored argiUo- calcareous indu- rated material, passing down into a gray clay, con- taining concretionary sandstone, sometimes an ag- gregate of angular grains of quartz, underlaid by a flesh-colored argillo-calcareous indurated stratum, containing a profusion of mamm.ali.au and chelo- nian remains. Turtle and Oreodon bed. Revealed on both sides of White River and through- out the main body of the Bad L<>rt l.iriii. (;. M. Wbeolui-'n Kxplorations West of 100th Meridian, voLiv,p.283. tSec Uana'fi Manual of Ocology, eilit. 18(;4, p. 511. t Bull. U. 8. Geol. Surv. Toim, v, pp. 50-52. BQUUS BEDS. 19 The material of the Ticholeptus horizon is a more or less finable argil- laceous sand ; not so coarse and gritty as the Procamelus bed, nor so cal- careo-argillaceous as the White River. The Procamelus bed is extensively distributed. It is found in Kansas, Nebraska, Colorado, New Mexico, Utah, Nevada, and Oregon. THE EQUUS BEDS. I can give little information respecting the depth and stratigraphy of the beds of this period as they occur on the plains west of the Missis- sippi River, for although sections of them as they occur in Nebraska and elsewhere have doubtless been published by authors, their paleontological status has not been determined for the localities described. My own knowledge of the deposits is based on localities in California and Oregon. In Nebraska they have probably been confounded with the Loup Fork, beds. They represent the latest of all the Tertiary lakes, and include a fauna which consists of a mixture of extinct and living species, with a few extinct genera. • I have received fossils of this age from Idaho, Washington, Oregon, and California. The most important locality in Central Oregon is from thirty to forty miles east of Silver Lake.* The depth of the formation is unknown, but it is probably not great. It consists, first, of loose sand above, which is moved and piled into dunes by the wind; second, of a soft clay bed a few inches in thickness ; third, by a bed of sand of 1 or 2 feet in depth ; then a bed of clay mixed with sand of unknown depth. The middle bed of sand is fossiliferous. In Northern and Middle Califor- nia the formation is chiefly gravel, and reaches a depth in some localities of several hundred feet. Here, as has been proven by Whitney, it con- tains human remains, associated with Mastodon, Equus, Auchenia, etc. I have obtained Mylodon from the same gravel. Traces of this fauna are found over the eastern United States, and occur in deposits in the caverns excavated in the Lower Silurian and Car- boniferous limestones, wherever the conditions are suitable. This deposit is a red or orange calcareous mud, varied with strata of stalagmite and * See American Naturalist, 1878, p. 125. 20 VERTEBRATA OF THE TERTIARY. gypsum. Remains of the fauna are found in clay deposits along several of the Atlantic Rivers, as the Delaware and Potomac. It is probable that the formation in the western localities mentioned is mostly sand. Near Carson City, Nevada, it consists of a light-buff friable calcareous sandstone. This is the Upper Pliocene of King, and the Post-Pliocene of various ■writers. Fig. tki. — Sinid Hills Noitliwe.steru Ni braska i'rom Hayden. sectio:n" II. THE HORIZONTAL RELATIONS OF THE NORTH AMERICAN TERTIARIES WITH THOSE OF EUROPE. Uniformity of system requires that an identical scale of stratigraphy be employed by all geologists. In accomplishing this object, the students of distinct regions necessarily rely on paleontology as the guide in making determinations of the relations of strata, since determination by observation of continuity is impossible. The progress of the vertebrate paleontology in North America of late years has been such as to permit of comparisons with the extinct faunae of Europe and other continents, which give definiteness to our knowledge of the relations between their geologic periods. Comparisons made by Mor- ton and Leidy had nearly determined the position of some of the eastern Cretaceoiis strata, and those of Leidy had approximately fixed those of the White River beds. Lyell and Conrad early deteimined the positions of the Eastern Tertiaries. My own views as to the European equivalency of our Keuper* and Laramie f were first expressed, and I later established the ages of the Wasatch, J Bridger,|| Loup River,§ and PermianT[ formations in America. A more detailed comparison being very necessary, I visited Europe in 1878 for the purpose of examining the rich collections of verte- brate fossils, and read a general synopsis of results before the Congress of Geologists of Paris of that year. The present section embraces a summary of that paper, with some additional matter.** The history of the succession of life upon any one portion of the earth's surface is replete with matter for speculation. It shows us a series of faunte succeeding each other, each of which, in many instances, com- mences without previous announcement in the forms of older periods, and 'Proceedings Academy Pliila., 18CG, p. 249. t Report on U. S. Geol. Surv. Forticlh Parallel, iii, p — . Trausac. American Pliilosophical See. , xiv, 1869, pp. 40, 98, 243. t Proceedings Amer. Philos. Society, February, 1872. II Loc. cit., August, 1872. § Annual Report U. S. Geol. Surv. Terrs. , 187:!, p. 402 ; Proceed. Academy Phila. , 1875, p. 257. f American Naturalist, 1878, p. 327 ; Proceedings Amer. Philos. Society, 1878, p. 530. * * This synopsis was first published in the Bulletin U. S. Geol. Surv. Terrs., v, p. 33. See Comptes Rendus St^nographiques, Congrfes Internationale de Geologic 1880, p. 144. 22 VEETEBRATA OF THE TERTIARY. disappears without leaving representatives in later ones. With this basis of fact, which naturally enough has been furnished by the longest explored and best-known portion of the earth, Europe, we turn to other lands, with the hope of obtaining further light upon a subject so full of mystery. These types of life, did they originate in a single centre, from which they disseminated themselves; and, if so, did each form originate in a region of its own, or not? Or, did the same types of generic structure appear at diflferent points on the earth's surface independently ; and, if so, whether cotemporaneously or at different times ? For a solution of these and similar questions, we naturally look to a comparison of the facts first established, with those obtained more recently by exploration in other regions. In this quest, no portion of the earth offers greater promise of results than America. As the second great con- tinent, separated from the other by the greatest possible water surface, we anticipate the widest diversity in the character of its life-history. If the types of life have originated independently, we will find evidence of it by studying American paleontology ; if their origin has been through gradual modification, America should furnish us with many intermediate faunee. Let us first consider the nature of the evidence on which we should rely in classifying faunse and the deposits which contain them. We are accustomed, at present, to rely for our definitions upon all the faunal peculi- arities upon which we can seize: the period of appearance of certain types; the duration of certain types; and the disappearance of certain types, depending on orders, families, and genera for the major divisions, and species at a given locality for the lesser. It is, of course, evident that either of the above-mentioned three criteria are variable quantities, since discovery is constantly extending our knowledge of the distribution of types. Hence the definitions are empirical and temporary. We must, then, if we desire a stable system, examine the principles involved, and endeavor to discover definitions which stand on stronger foundations than those which we now possess. As a matter of fact, the old definitions of epochs and periods are con- tinually invalidated by new discoveries. As a matter of theory, this should be the case. DISCEIMINATION OF EPOCHS. 23 To the believers in the doctrine of derivation, the obliteration of faunal distinctions is not a cause of surprise. Such await with confidence the day when complete phylogenies will be possible, and at present regard the inter- ruptions in the succession of life as local only. Will the result then, be, that paleontology will cease to be available in the definition of ages and of deposits ? I answer no, on various grounds. Interruptions in the succes- sion of life in any given locality, due to various causes, have doubtless often occurred, and have left traces in the crust of the earth which are ineffaceable by discovery. But apart from this, one fact in this history is patent both to the friends and to the opponents of the doctrine of derivation: It is known that the world has witnessed, at every stage of its history, the extinc- tion of some important type of life. Familiar examples are the Placodermi of Paleozoic time, various reptilian groups of Mesozoic time, and the Amhly- poda of the Tertiary. Each minor subdivision of time ofi'ers its own record of persistences and extinctions of particular families and genera. Now, all departments of biology compel us to recognize the law of classification, that the order of forms is from the less to the more generahzed, from the simple to the more complex, and vice versa, whether the lines of succession be those of descent or of creative order ; and this law is true in time as well as in classification. It follows from this, that all types of life are, at the time of their appearance, less distinct and more general in their characters than they are later in their history. . It also follows, as a consequence of the principle of descent, which states that the types of one age have taken their origin from generalized types of preceding ages, that there is no descent from the most specialized types ; which is to say, conversely, that the genera, families, and orders whose extinction has been a marked feature of every geologic age have been the specialized types of those ages. We now have a clue to. a basis of a definition for faunae, and hence for epochs, which discovery can safely build upon. The successive increments of structure by which an important modification of animal type is intro- duced, preclude the possibility of exact determination of the time at which such type may be said to have appeared. Even where such a point may be arbitrarily fixed, the type must then be less characteristically represented 24 VERTEBRATA OF THE TERTIARY. than it is at the other Hmit of its existence, viz, the period of its disappear- ance. For these reasons I must regard tlie latter criterion as the true one in the discrimination of the subdivisions of geologic time, while the point of the appearance of types must be looked upon as of provisional use only, and this quite independently of the changes which discovery will from time to time compel us to make in our knowledge of the distribution of life in time and space. It must, however, be borne in mind that disappearance may be due to two causes : first, to extinction ; and secondly, to modifica- tion ; a distinction which is entirely essential. The case of disappearance by modification is identical with that of appearance by modification, and cannot be used otherwise in classification. It is, then, the period of extinc- tion of types to which I have reference. With these principles in view, we attempt the comparison of the ex- tinct faunae of Europe and North America, employing principally the nomenclature of D'Orbigny for the former, and Hayden for the latter, in the Mesozoic and Tertiary series. It is well known that no remains of Vertebrata have yet been discovered in North America in strata of Silurian age, while several species are known from the Upper Silurian of Europe. The latter are Placodermi and sharks, and are not very numerous in species. They have been derived from England, Gennany, and Russia. In America, the first fishes appear in the Comiferous limestone at the base of the Devonian. Professor Newberry, who has devoted much attention to this department, points out important distinctions as existing between the Devonian fish faunae of North America and Europe, and also to important coincidences. The first of these is the occurrence of the genus Macropetalichthys in both continents; in Germany in the Eifel limestone, and in America in the Corniferous limestone of Ohio. The other examples are furnished by the Catskill beds of New York and Pennsylvania, which contain a part of the fauna of the old Red Sandstone of Scotland, including the genera Holoptychius and Bothriolepis* The structure of the Batrachia of the Coal-Measures is not yet suffi- ciently well known to enable the most exact comparisous to be made, but • Oeological Survey of Ohio, i, pp. 264, 271. PALiEOZOIC AND MESOZOIC. 25 close parallels, if not identities, of genera exist. Such are the OesfocepJialus and Ceraterpeton of Ohio as compared with the Urocordylus and Ceraterpeton of Great Britain. The Permian vertebrate faima which I discovered in Illinois and Texas exhibits close parallels, but not yet generic identity, in the two continents. Thus, the American Clepsydrops and Dimetrodon are near to the Beutero- saurus of Penn, in Russia, and the Lycosaurus of the mountains of South Africa. The Texan genus Parioticlms may, with further information, prove to be identical with Procolophon Ow. from the Tafelberg. Humeri of the type discovered by Kutorga in Russia, and by Owen in South Africa, are found in North America, and the same remarkable type has been recently discovered by Gaudry in France. The peculiar type of Ganocephalous vertebrae described by me under the genus Rhachitomus from Texas, has been discovered by Gaudry in France. The even more remarkable Cricotus (Cope), type of the Emholomera, is paralleled by the Biplovertehron (Fritsch) of Bohemia. Edosteorhachis represents in Texas the genus Ilegalichthys. The present indications are that close similarity between the faunae of this period in Europe and America will be discovered. Nevertheless, up to the present time no representatives of the striking American forms Bolosaurus, Diadectes, and Empedocles have yet been found in any other continent. As regards the Triassic fauna, it differs from that of the Permian in being better known in Europe than America. As marine Trias is little devel- oped in North America, so the vertebrate fauna of the Muschelkalk has not been discovered in the latter country. It is otherwise with the Keuper. The characteristic genus of that epoch, Belodon, existed in America, and parallels, if not identity, are seen in the genera Thecodontosaurus and Palceosaurus. These are known in America from teeth only. The reptiles are accompa- nied in North America, as in Europe, by Stegocephalous BatracJiia, mostly Labyrinthodonts, but their generic affinities are yet unknown. The great Jurassic fauna^. are as yet but sparsely represented in North American paleontology. The marine Vertebrata of the Lias are either unknown or are represented by a few provisional identifications of unsatis- factory fragments. "We do not yet know any deposits in North America which contain the typical reptilian genera Plesiosaurus, Ichthyosaurus, Plio- 26 VERTEBRATA OF THE TERTIARY. saurus and Dimorphodon, or the fishes of the Dapediidce. This formation, 80 important in Europe, is almost omitted from the North American series. Several characteristic fossils of the Rocky Mountain region represent the Oolite, particularly the Upper Oolite. Such is a genus not yet distinguisli- able from Megalosaurus. This genus has not been identified beyond doubt from above the Oolite in England. Teleosaurus and Steneosaurus, and their allies, are not yet known from North American beds. From the same beds in the Rocky Mountain region come genera which nearly resemble the one from the English Oolite (Forest Marble) called by Phillips Cetiosauriis, and the genus from the Oxfordian of Honfleur, called by von Meyer Streptospondylus. Beyond this no comparisons can be made, and we therefore pass to the rich fauna of the Kimmeridge. North America cannot show such records of this epoch as have been found in Europe There are no Archceoptenjx, Bhamphorhynchus, nor Pterodactylu^-^; no Leptolepis, Thrissops, nor other of the numerous fishes of Solenhofen. The Omosaurus has, however, some very close relatives in the Camara' saurus beds of the Rocky Mountains. Remains of the primitive Mar- supial fauna which occurs in the Purbeck have been recently detected in the Western Continent. A partial representation of the Wealden fauna of Europe is found in the beds of the Rocky Mountains mingled with the types of the Oolite and Kimmeridge already mentioned. The important genus Camarasaurus represents the Ornithopsis of Europe, and with Amphi- codias included the most gigantic of land animals. The relationships of this fauna to those of the European Jurassic series may be thus exhib- ited: American. Kiiroiiciin. Camarasaurus Beds. "Wealden. f Iguanodon. f Ilypsilophodon. Hypsilophodon. Hijlceosauriis. t Cettosaurus. Cetiosaurus. Camarasaurus. Ornithopsis* Amphica'lias. fGoniopholis. GoniopJwlis. 'CJumdrotttotaurut Owen. MESOZOIO. 27 American. European. KiMMERIDGE. HypsirJiophus. Omosaurus. Caulodon. f Caulodon.* Oxford. Epanterias. Streptospondylus. Oolite. " Cetiosaurus." ? Megalosaurus. Megalosaurus. From the above table it will be seen how difficult it is to parallelize the related beds of the Jurassic periods of the two continents at the present time. All that can be said is, that many types resemblingf nearly those of different horizons of the European Jurassic are found to have lived together or near together in the Rocky Mountain region of North America. That the Cretaceous fauna of North America was the richest in the cold-blooded Vertehrata is indicated by the present state of discovery. The ocean of the interior of the continent deepened from the beginning of the period until the epoch of the Niobrara, and then gradually shallowed until the elevations of the bottom began to divide the waters. The closing scenes of this great period were enacted amid a labyrinth of lagoons and lakes of brackish and fresh water, whose deposits form the beds of the Laramie epoch. The fauna of the deep-sea epoch, the Niobrara, is the best known. Here the i-emains of Pythonomorpha constitute its prevailing characteristic, while Elasmosaurus and Polycotylus, with but few species, represent the numerous Sauropterygia of Europe. Crocodiles were apparently wanting, while turtles and a peculiar group of Pterosauria were only moderately abundant. The fish fauna was very rich and varied. Here the Saurodon- tidcB, like the molluscous family of the Eudistes, appeared and as soon dis- * Iguanodon prcecursor Sauv. t A near affinity has been shown by Professor Owen to exist between Eucamerotus and Camarasau- rut. Profegaor Owen believes these genera to be identical ; bnt the neoral spines of the anterior dorsal vertebra are very different, being single in the former and doable in the latter. 28 TERTEBEATA OF THE TERTIARY. appeared, accompanied by the peculiar form Erisichthe, and the family of StratodontidfB. The genera of Mount Lebanon, Leptotrachehts and Spanio- don, occur in this bed in Dakota ; but the closest parallelism is exhibited with the Lower Chalk or Turonian of Western Europe. The general fades of the reptilian fauna is that of the Lower Chalk, and there is little doubt that several genera are identical in the two continents, e. g. Elasmosauru^. The apparent peculiarity of the Chalk in America is the abundance of forms (four genera) of Fi/lhonomorpha, with numerous species, while but two genera have yet been found in Europe, and the presence of birds with biconcave vertebrae and teeth. This interesting type, which was first dis- covered by Seeley in the genus named by him Enaliornis, and afterwards found by Marsh to possess teeth, has been found at a lower horizon in England, the Upper Greensand. But in England, France, and Westphalia occur the genera of fishes above mentioned, as Portheus, Ichthyodectes, Saic- rodon, Saurocephalus, Erisichthe, Empo, Pachyrhizodus, Enchodus, Leptotra- chelus, etc. This close relationship of the horizons permits an identifica- tion, and it is the first instance which appears to me to be susceptible of satisfactory demonstration. The next horizon of the Cretaceous which has yielded many verte- brate remains in North America is the Fox Hills formation (including the Fort Pierre bed). Here the genus Mosasaurus appears in America, and is accompanied by the earliest crocodiles with procoelous vertebrae, and by numerous marine turtles which partake of the characters of both CMydri- d(B and Cheloniida, which I have called the Propleuridce. Beryx appears first here in America. The predominant genus of fishes is Enchodus, and the principal Dinosauna are Lcdaps and Hadrosaurus. This horizon has been ])arallelized with the Maestricht of Europe, and several genera are common to the two beds ; such are Mosasaiirus and Enchodus. The genus Hadro- saurus, and the family of turtles I have called the Adocida, remain undis- covered in Europe ; hence the identity of faunaj cannot be established. The lacustrine beds, or summit of the American Cretaceous series, the Laramie of Hayden, present the remains of a populous fauna and a rich flora. The students of the palneobotany have declared this flora to be of Eocene, and the later portions of Miocene, character, while tlie lacustrine MESOZOIC. 29 constitution of the strata has influenced the stratigraphic geologists to con- cur in the view that the formation should be arranged with the Tertiary epochs. That the fauna was of a mixed character is the result of a study of its vertebrate fossils. The predominant type in North America was the Dinosauria, which were abundant in species and individuals, and this fact alone will suffice most paleontologists as a reason for referring the epoch to the Cretaceous series. The genera of Dinosauria (Palcsoscincm, Ciono- don, Diclonius, Monocloniiis, Bysganus, etc) have not yet been found in any other part of the world. Mingled with them were species of crocodiles and turtles of indifferent character, while a number of other forms existed which had a limited range in time, and hence are important indicators of stratigraphic position. Such are the genera of fishes, MyledaijJius Cope and Clastes Cope, which have been found also near Reims, France, by Dr. Lemoine, in the Sables de Bracheux, which are regarded as the lowest Ter- tiary. Such is the curious Saurian type Champsosaurus (Cope) {Simcedo- saurus Gerv.), and the turtle genus Compseniys Leidy, which Lemoine finds a little higher up in the series, in the conglomerate of Cerny, which is in the lower part of the Suessonian. In France, a genus of the Laramie, Polythorax, extends into the Lignite or Upper Gorypliodon bed of the Sues- sonian Thus the Laramie is intercalated by its characters between the Cretaceous period on the one hand and the Tertiary on the other, and its fauna includes genera and orders of both great series. These relations may be exhibited in tabular form as follows. I here include the faunae of the Sables de Bracheux and of the conglomerate of Cerny as one, since both possess the types of the Laramie, while the horizon of the Lignite of Meudon, or the Suessonian, does not. Sables de Bracheux and Con- Laramie. GLOMERAT DE CeRNY. a. Teetiaey. Lophiochosrus. Plesiadapis. Pleuraspidotherium. Arctocyon. Clastes. Clastes. 30 VERTEBRATA OF THE TERTIAEY. y?. Peculiar. Champsosaurus. Compsemys. Myhdaphus. Sables de Bracheux and Con- GLOMEEAT DE CeENY. Champsosaurus. Compsemys. Myledaphus. Scapherpeton. Laeamie. y. Ceetaceous. Pakeoscincus. Dysganus. Monoclonius. Diclonius. Cionodon. Lcelaps. Auhhjsodon. If the Conglomerate of Cemy be the same horizon as the Conglomerate of Meudon, we must add Coryphodon to the upper left-hand column, and probably Gastornis also. The i*esult is clear that the French and American formations together bridge most completely the interval between the Cre- taceous and Tertiary series, as has been anticipated by Hayden, in America, on geological grounds. It is also evident that another formation must be added to the series already recognized in France, viz, the Laramie or Post- Cretaceous. Tliis will be defined as the beds of the genera Champsosaurus and Myhdaphus. In France, the presence of mammalia will characterize the formation as a subdivision, for which it is probable that the name Thanetian must be retained ; while to the American division, which is characterized by tlie presence of Dinosatiria, the name of Laramie beds has been given. In arranging the Laramie Group, its necessary position is between Tertiary and Cretaceous, but on the Cretaceous side of the boundary, if we retain tliose grand divisions, which it appears to me to be desirable to do. The reasons for retaining it in the Cretaceous are two, viz: (1) because EOCENE. 31 Dinosauria are a Mesozic type, not known elsewhere from the Tertiary; (2) because Mammalia (should they be found in the future in the Fort Union) are not equal as evidence of Tertiary age, since they have been also found in Jurassic and Triassic beds. The Eocene fauna is so varied, especially in Europe, that it is neces- sary to compare the divisions separately, as in the case of the Cretaceous. Thus, the fauna of the Suessonian is quite as distinct from that of the Cal- caire Grossier and Gypse (Parisian and Tongrian) in France as are those of the Wasatch and Bridger epochs in North America. I have already identified the Wasatch with the Suessonian or Orthro- cene, on account of the community of the following genera in the two continents: Coryphodon, Hyracotherium, Amhly clonus, Clastes, and a form of birds close to Gastornis. I can now add Phenacodus, Orotherium (Cope), and very probably Hyopsodus, Adapis, Opisthotomus, and Prototomus. But, as above mentioned, in the lower beds of the Suessonian in France occur genera which are, so far as yet known, wanting in the Wasatch of America, but present in the beds of the Laramie. The parallelism of the American Wasatch with the Upper Suessonian of France is the second identification which may be regarded as provision- ally established. The only important discordant element at present known is the Tceniodonta of the Wasatch, which have not so far been found in Europe. Above the Suessonian, a divergence in the characters of the European and North American faunae commences, and continues to be marked through- out the remainder of Tertiary time. So far as the Mammalia are concerned, the diversity between the continents was greater during the periods of the Upper Eocene and Miocene than at the present era. During these periods, a limited number of genera, common to the two continents, was associated with numerous genera in the one which did not exist in the other. As a consequence, our paleontological means of identification of the horizons are limited to a restricted list, and the task of applying a uniform nomencla- ture is, under the circumstances, diflScult. Another difficulty in the way of determining the place of the American beds in the Eui-opean scale consists in the fact that the physical history of the two continents dui'ing the Ter- 32 VERTEBRATA OF THE TERTIARY. raiy period appears to have been different. In America, the changes of evel appear to liave been more uniform in character over large areas. Each deposit has a wider geographical extent, and the fauna presents less rregular variation. In Europe we have a great number of comparatively estricted deposits, each of wliich differs from the others in possessing more or less peculiarity of fauna. After a study of these faunae, their natural arrangement in Europe into three series — Eocene, Miocene, and Pliocene — does not appear to rest on any solid basis. This is especially true of the distinction between the first two; and authors are at variance as to the point of demarkation between the last two. Thus, the Tongrian is the summit of the Eocene according to Renevier, while Gaudry, with Filhol and others, places it at the base of the Miocene. One opinion is as well supported by facts, as now interpreted, as the other. As an essential aid in the estimation of the Hmits of the formations, I appeal to the criterion adopted at the opening of this chapter, viz, the period of extinction of animal groups. If we take a general view of the Tertiary faun£E, we find that the fol- lowing well-marked types representing famiUes and higher groups have become extinct, and have left no living descendants or successors : Among Bunotheria, the American groups Tceniodonta and Tillodonta ; also the Meso- donta of both continents; of Edentata, Macrotherium, and Ancyhtherium in Europe, and the 3IegatJieriidce in North America; among the Carnivora, the Eyanodons and Proviverrce, with the Drepanodons ; of Ungidata, the entire order of Amhlypoda, which, however, doubtless disappeared in some of its members by modification ; but its only known suborders, the Pantodonta and the Dinocerata, become absolutely extinct. Among Perissodactyla, both continents lost by extinction the ChaUcotheriidcB, which terminated in a great development in North America; and the Bhinocerida. Of Artiodactyla, two great divisions, representative of each other in the two continents, totally disappeared, viz, the OreodontidcB and the Anoplotheriida ; to which must be added the Hyopotamidfc. Of true ruminants, the most important type which has disappeared from both continents is that of the Cameltda, Oi 8u\\\hw gauera, Anthracotherium and Elotherium may be looked upon as EOCENE. 33 having left no persistent successors. Last of all, the Proboscidea retreated to the continents of the south. In view of the complexity of the European record, I first present the relations of the above-mentioned phenomena as displayed in the simpler American system. As the present essay commences with the earliest periods, I exhibit the succession in descending order on the page. The horizons of the Tertiary which present distinct terrestrial faunae in North America have been named the Wasatch, the Bridger, the Uinta, the White River, the Loup Fork, the Equus beds, and the Champlain. The types which became extinct* with the close of each of these epochs are the fol- lowing : Wasatch. White Rivek. Gastornithidae. Leptictidce. Pantodonta. Hycenodon. Bridger. Ghalicotheriidee. BaenidcE. Hyopotamidce. Tillodonta. Loup River. Stypolophuis. Mhinoceridce. Dinocerata. Hippotherium. Uinta. Oreodontida. fMesodonta. Equus Beds. Amynodon. Megatheriidee. Drepanadon. Tapiridce. Elephas. CamelidcB. The above table exhibits the present state of our knowledge ; it will doubtless be much extended by future discovery, but not otherwise modified. The numerous able writers on European vertebrate palaeontology have more frequently recorded the appearance of types in defining their faunal • This means, as already mentioned, the forms which left no direct snccessoTs in the Nearctio and and Palasarctic faunae. 3 C 34 VERTEBRATA OP THE TERTIARY. divisions than their disappearance. The follo\ving table is compiled from the writings of Gervais, Gaudry, Pomel, Filhol, Renevier, and others, but is not as complete as I would desire. SUESSONIAN. FaLUNIAN. Pantodonta. Anchitherium. Parisian (Bruxellian, Bartonian, Anthracotherium. and Sestian). Paheochcerus. Pal(eoj)his (Bruxellian). Ccenotherium. Proviverra. Oeningian. Pterodon. AncyJotherium. Mesodonta. Dinotherium. Lophiodon (Bruxellian). Hippotherium. ToNGRiAN. Aceratherium. PakEotheridce. Subapennine. Chalicotherinm. Mastodon. Anoplotheridce. Tapirida. JSlotherium. Diluvial. Aquitanian. Hycena. Hycenodon. JDrepmiodon. Hyopotamus. Elephas. Ehinocerus. Hippopotamus. The above tables show that the history of mammalian life in the two continents presents many points of resemblance ; but that there is a great difficulty in coirelating the epochs represented by the known faunjE. As regards the two primary divisions, Eocene and Miocene, they have no special raison d'etre, as such faunae as the Tongrian and Oeningian are absolutely transitional in their character. More detailed comparisons of the European and American faunae bring out many relationships not displayed by the above tables, and which I will now briefly consider. In the American Bridger, various genera of Mesodonta represent the few Adapidae of the Parisian, the genus Adapts* Cuv. being probably com- mon to the two continents. A near ally of the American Anaptomorphus, a * A'otharctut i» undiatingaiBhuble from Adapis in inferior dontal cboracttini. EOCENE. 35 true Lemur, has been found by M. Filhol in tlie Phosphorites, and named Necrolemur. The characters of the numerous Carnivora of the Bridger are as yet unknown. The Stypolophus of the Bridger is perhaps the Pro- totomus of the Wasatch, and this again has been discovered by M. Filhol* in France ; while a very similar genus has been discovered in the Swiss Siderolitic, and named Proviverra. Hyanodontidce probably occur in the Bridger. Nowhere in Europe do we find the Dinocerata and Tillodonta of the Bridger. Palceosyops is also unknown in Europe, but it plays the part in America of the Palceotherium,, from which it does not greatly differ in structure. The latter genus is most largely developed in the Parisian, but is also characteristic of the Tongrian. Hyrachyus is the American Lophi- odon, the difference between them being but slight; both are found in France ; the former in the Lower Parisian, the latter in the Phosphorites. Tapirulusf Gerv. is a genus common to the Bridger and to more than one horizon of the Parisian. The squirrel-like rodents of the Bridger are like those of the Parisian, but they are not confined to either epoch. The char- acter which distinguishes the Parisian most widely from the Bridger, besides the absence of the Dinocerata and Tillodonta, is the presence of numerous Selenodont Artiodactyla, as Xiphodon, Ccenotherium, Amphimeryx, Anoploiherium, etc. These are of primitive type, it is true ; the Anoplothe- riida especially having probably four toes in the very short manus {Eury- therium), including the poUex, and three behind. They also display the character of a fifth crescent of the superior molars, which is wanting in the higher Selenodont types. But even these genera are absent from the Bridger. The ensemble is then that the latter displays relationships back- wards, or to the Suessonian, while the Parisian has a later fades, consti- tuting an approach to the Tongrian and White River. J The following table presents the relations of the Bridger fauna suc- cinctly, but it is much less complete than we hope to make it when its numerous species are fully described. The Parisian is here regarded as including the divisions Bruxellian, Bartonian, and Sestian (Gypse). * It is described as Cynohijcenodcm with two species. tGervais, IHoO ; Helaletes Marsh, 1872, vide Scott, Spier, and Osborne. t See Ann. Kept. U. S. Geol. Snrv. Terrs. 1873, pp. 461-462, where this view is proposed. 36 VERTEBKATA OF THE TERTIARY. Parisian. Didelphys. Vespertilionida. Plesiardomys. HycEnodontidcB. Adapis. Necrohmur (Phosph). Bridger. f Didelphys. VespertilionidfP. Plesiardomys. Tillodonta. HycBnodontidcB. Adapis. f Ui.Tr«iwU>j Anaptomorphvs. Dinocerata. PalcEosyops. Palceotherium. Lophiodon. Hyrachyus (Phosph.). Hyrachyu-s. Tapirulus. Tapirulus. Anfhracotherium. Achcenodon. Chceropotamus. Dichohune. Anoplotherinm. Xiphodon. Amphimeryx. The rich Tongrian (Stanipian) fauna is, according to authors, repre- sented in the Sables de Fontainebleau, Pay en Velay, Ronzon, Hempstead, and Cadibona in Italy. We find here Didelphys in abundance, Hyanodon, Amphicyon, Canis, Palceotherium, Paloplotheriuni, Oialicotherium, and Ace- ratherium. Of Artiodadyla, the Suillines are Anthracotherium and Elothe- rium; the Selenodonts, Hyopotamus and Gelocus. This list is the nearest known counterpart of that of the fauna of the White River epoch of North America. To reproduce the latter we must omit from the above catalogue the genera of Palccotheriidoe, and replace them by the allied Clialicotheroid Menodus and Symhorodon, subtract Anthracotherium, and add the great body of the Orcodontida: Then there are included in the White River fauna the higher Selenodont Artiodactyles of the Poehrotheriidw and Hypertragulida^, the corresponding types of which belong to the fauna of St Gerand le Puy in France, or the Aquitanian epoch, which directly succeeded the Stam- pian. In Europe, we have here Dremotherium, Amphitragnlus, Lophiomeryx, MIOCENE. 37 Dorcatherium ; in America, Leptomeryx, Hypertragulus, Hypisodus, and Poe- brotherium. It is curious that while Leptotneryx is also European,* it has not yet been found above the Phosphorites. Among Suillines, the Paloeo- chcerus\ of the Oregon White River beds has also not been found below the Aquitanian in Europe. But the American DidelphysX Hywnodon, Amplii- cyoti, Elotherium, and Hyopotamus, with the numerous Chalicotheroid species, show clearly that the White River fauna may be looked upon as a mixture of those of the Stampian and Aquitanian, the former of which is sometimes referred with reason to the Upper Eocene, while the latter is always left in the lowest Miocene. And the solution of this question of position as regards the White River beds appears to me to be at present by no means €asy.§ According to the system of Naumann, it should be called Oligocene. Although Artiodactyles with Selenodont molars are far more abundant in both continents during this period than the last, a remarkable difference is to be observed between them. Those of Europe still largely consist of the types with five crescents, as represented by the numerous Hyopotami and Ccenotheria, while in America the modern fom*-crescent-bearing molar characterizes almost the entire suborder, the only exception being two species of Hyopotamus. The following table will represent the relations of the White River fauna: Stampian and Aquitanian. White River. Didelphys. Didelphys. Leptictidce. ProtomyidcB Protomyid(B.\\ Saccomyidce.^ Stampian and Aquitanian. White River. Steneofiber. Steneofiber. Leporidce. Leporidce. * I think M. Filhol's Prodremoiherium is identical Trith Leptomeryx. t Tkinohyus Marsh appears to be the same, t Herpetotherium Cope ; Peratherium Aym. J See Ann. Report U. S. Geol. Surv. Terrs. 1878, p. 462, where the White River beds are deter- inined as Lower Miocene. II Ischyromya Leidy. IT Enioptychua and FlearoUeus Cope. / 38 VERTEBRATA OF THE TERTIARY. Stampian and Aquitanian. Hycenodon. Amphicyon. Cants. Giilo.* Pro(elurus. Adurogale (Phosp.). PaleeotheriidcB. Aceratherium. JElotherium. Paleeochoerus. Anthracotherium. Anophtlieriidce. HyopotamidtE. Lophiomeryx. Amphitragidus. Leptomeryx (Phosph.). Dremotheritim. White River. Hyanodon. Amphicyon. Cants. Temnocyon. Enhydrocyon. Gulo.* Archalurtis. Nimravus. Dinictis. Hoplophoneus. Chalicotheriida. Hyracodon. Aceratherium. Anchitherium. Elothcriwn. PalcBochoerus. Oreodontidce. Hyopotamidce . Poebrotherium. Hypertragulus, Leptomeryx. Hypisodus. The Falunian epoch includes in the large sense the Langhian, HeWe- tian, and Tortonian divisions, embracing the rich deposits of the Orlcanais, of Simorre, and of Sansan. We have here the true Miocene fauna, of wliich the following genera are characteristic: Edentata, Macrotherium ; Probo- scidea, Dinotheriitm, Ma.stodon; Perissodactyla, Anchitherium, IJstriodon; * Amphiclin Pom. t Copi! 1H74 ; /VoecrruJun. Oaiidry, 1878; Dicrooeriu Copo, 1874 (uot Lurtot) ; Merycodut et CotoTj/z Leidy, nomina nudn. MIOCENE. 39 Artiodactyla, Palceomeryx, Bicrocerus, Cosoryx;\ Carnivora, AmpMcyon, Hyeenarctos, Brepanodon ; Quadrumana, Pliopithecus. The ancient genera Anthracotherium and Ccenotherium continue throughout, and the existing genera Arvicola, Lutra, and Sus appear. The succeeding epoch, the Oenin- gian, including with it the horizons of Epplesheim and Pikermi, presents the additional genera Borcatherium, Helladotherium, several genera allied to Antilope, with Hippotherium, the huge edentate Ancylotherium, and the monkey Mesopithecus. It is from these materials that we must determine by comparison the American Loup Fork epoch, whose deposits are widely spread, and whose fauna is of well-marked character. Although called by my predecessors Pliocene in age, I have insisted that it should be referred to the Miocene series, and I think that the evidence to that effect which I have produced will be found conclusive. Nevertheless here, as in other American Ter- tiary horizons, the element of geographical peculiarity enters, and diminishes the number of identical types. Falunian. Steneofiber. Macrotherium. Ancylotherium. Amphicyon. Binotherium. TetralopJiodon. Aceratherium. Anchitherium. Listriodon. Hippotherium (Oeningian). Ccenotherium. Anthracotherium. Palceomeryx. Bicrocerus. Loup Fork. Steneofiber. Mylagaulus. Morotherium. Amphicyon.* Gcenobasileus. Tetralophodon. Aphelops. Hippotherium. Protohippus. Hipjndium.f Oreodontidce. Blastomeryx. • CanU ursinua Cope. t PUoMppus Marsh. 40 VERTEBRATA OF THE TERTIARY. Falunian. Loup Fork. Cosorijx. Cosoryx. Protolahis. Procamelus. The existing genera mentioned as found in the Falunian fauna are paralleled by the Dicotyles, Hystrix, and Mustela of the Loup Fork beds. It is e\'ident that this latter horizon retains in its Oreodontidce the same traces of antiquity that the Falunian does in its Ccenotherium, but shows a more modem aspect in the omission of Anchitherium and its replacement by Hippotherium and ProtoMppus, and in the still more modern type Hippidium. Although but six genera of the two continents are determined as identical in the above table, yet others, which are facing on the same line, are very nearly allied. Other differences are geographical. The facies of the Loup Fork horizon is then a compound of that of the Falunian and Oeningian, or Middle and Upper Miocene. In commenting on the above-described fauna in 1874,* I remarked that "the proper discrimination of the American Pliocene remains to be accom- plished." It was not long after that date that material for making the identification of this horizon on this continent first came into my hands. This was derived from the superior Tertiary of Oregon, and includes a con- siderable number of species of fishes, birds, and Mammalia. I published a list of some of the species in 1878.t The character of the fauna from that region coincides with that which has from time to time been unearthed in the caves and other Eastern deposits, to such an extent, as to lead us to suspect that the differences between them are geographical only. In Em*ope the Pliocene, or Subapennine, includes, according to D'Orbigny (1855) and Gaudry (1878), the Plaisancian and Astian, which are represented at the following localities : Subapennine. PlaUancian. — Montpellier; Casino (Tuscany). Antian. — Perrier, near Issoir, Ooiipet, Vialette (Upper Loire), Chagny; English Orag; part of deposits of the Val il'Arno. Tlie characteristic of this fauna is the fact that the species belong • Report Lient. G. M. Wheeler, iv, Paleontology of New Mexico, 1874, p. 364. fBuU. Hayden'8 U. 8. Geol. Snrv. Terra, iv, 187ti, p. 389. EQUIVALENCY OF BEDS. 41 mostly to existing genera, the chief exception being Hippotherium. The horses are chiefly represented by Equus. Common genera are Ardomys, Lepns, Elephas, Mastodon, Tapirus, Sus, Cervus, Antilope, Bos, Canis, Drepa- nodon, Felis, Ursus. In the Equus beds of Oregon a few extinct genera in like manner share the field with various recent ones, while not a few of the bones are not distinguishable from those of recent species. I give the fol- lowing list, the extinct species being in italics : Mylodon sodalis. Canis latrans. Thomomys (nr.) clusius. Elephas primigenius. Equus occidentalis. Equus major. Auchenia hesterna. Auchenia magna. Auchenia vitakeriana. Cervus fortis. Thomomys talpoides. Castor fiber. l/utra near piscinaria. The species derived from the cave formations of the Eastern States are more numerous, and diflfer from the Oregon fauna in many respects ; yet the parallelism is close in the genera with the Equus beds on the one hand and the Pliocene of Europe and South America on the other. The differences distinguishing it from the Equus beds of Oregon are, however, such as compel me to regard it as a distinct division of the Pliocene, under the name of the Megalonyx beds.* Megatherium (p). Mylodon (p). Megalonyx (p). Sciurus (s). Arctomys (s). Jaculus (s). Arvicola (s). Erethizon. Hydrochcsnis (p). Castoroides. Lagomys (s). Lepus (s). Anomodon. Scalops. Arctotherium (p). Procyon. Canis (sp). DrepanodonSmilodon (vel). Mastodon (sp). Equus (sp). ? Hippotherium (s). Tapirus (s). Dicotyles (p), Cariacus (p). Bos (s). Mustela (sp). In the above list the extinct genera are marked in italics. There exists, as a marked feature of the North American Pliocene, to which I called attention several years ago,t a considerable representation of the fauna of *BuU. U. S. GeoL Surv. Terrs, v, p. 5a, 1879. \ ProcAoad. PhUa. 1857, 156; Proc. Am. Philos. Soc. 1869, 178. 42 VERTEBRATA OF TDE TERTIARY. the Pampean formation of South America; such are twelve genera, of which six are extinct genera, and four are pecuHar to that formation and fauna. The genera found in the Pampean are marked (p), and those of the Subapennine (s). In the list from the Oregon localities, Mylodon and Auchenia were observed to be the only distinctively Pampean genera. As a conclusion of the comparison of the American Equus beds in general with those of Europe, it may be stated that the number of identical gen- era is so large, that we may not hesitate to parallelize them as stratigraph- ically the same. On the other hand, the agreement with the South Ameri- can Pampean formation is so marked in some respects as to induce us to believe that the distinction is geographic rather than stratigraphic. Believ- ing that the Pampean formation contains too large a percentage of extinct genera to be properly regarded, as it has been, as Post-Pliocene or Quater- nary, its characters, both essentially and as a result of the comparison which I have been able to make, refer it properly to the Pliocene. It appears, then, that the term Pliocene or Subapennine is appHcable to the horizon of this fauna in Europe and North and South America. RESUME OF COMPARISONS. The conclusions to be derived from the facts enumerated in the pre- ceding pages are as follows: I. Portions of all the faunae of all the primary divisions of geologic time have been recognized on both the European and North American con- tinents. II. Parallels requiring general identification of principal divisions of these faunaj may be detected. These are: the Coal Measures; the Per- mian; the Laramie; the Maestri chtian; the Eocene; the Miocene. III. Exact identifications of restricted divisions maj' be made in a few instances only; such are the Turonian and the Niobrara; the Snessonian and the Wasatch; the Equus beds and the Pliocene. It is not impossible that some of the relations mentioned in II will be by the accession of further information, referrible to the list of exact com- parisons in III. In iill cases of identification it will be necessary to employ the name first proposed with definition for the horizon, other names taking KOMECLATUEE OF FORMATIONS. 43 places as synonymes But in the majority of strata it will be necessary to preserve the special names : thus those of Bear River, Bridger, White River, and Loup Fork, applicable to beds having no exact equivalents in Europe, cannot be set aside for older ones, but must themselves be applied to cor- responding faunal horizons elsewhere, should any such be found in future. And it will rarely happen that the minor subdivisions of such faunae will be found to have an extent sufficient to warrant their having other than special names. In the accompanying diagram the series of strata of Europe and North America, as determined by their paleontology, are placed side by side for the purpose of comparison. Complete parallelism can only be predicated of divisions of the first order, separated by horizontal lines. Such relation is indicated by exact opposition of the areas representing the epochs in question. In giving the minor divisions of the European epochs I have generally restricted myself to those of the epochs which have American equivalents. Where there is no equivalent on one side or the other, the vacancy is represented by a diagonal Hne. In employing names for epochs and their divisions, I have adhered to the law of priority as far as my knowl- edge of the literature allows.* I have given a few names to American for- mations, but only in instances where such had not been previously given. In such cases I have pieferred employing the name of some characteristic genus of fossils, rather than one of local origin. COMPARISON WITH THE SCALE DERIVED FROM PALEOBOTANY. I now consider another kind of relation presented by the American and European horizons. I allude to the florae, for my knowledge of which I am necessarily dependent on the labors of others. I first exhibit the deter- minations of the ages of the American formations, already discussed, made by Mr. Lesquereux on the basis of the vegetable remains which they contain. I place by the side of these my own determinations of the ages of the same beds, as already related. The former are derived from the full memoir of Mr. Lesquereux in the Annual Report of the United States Geological Sur- * In the European system I have been much aided by the writings of Woodward, Gervais, H6bert, Pomel, Gaudry, etc., and by the atlas of Professor Renevier, of Lausanne. 44 VERTEBKATA OF THE TERTIARY. vey of the Ten-itories for 1872, pp. 410-417. It will be observed that there is a constant discrepancy between the two tables. Losqucrenx. Formation. 1 Cope. Loup Fork . Miocene. White River Oligocene. Upper Miocene Miocene Lower Eocene j Wasatch » ( Green Hi vcr J Lower Eocene. Upper Cretaceous. It" the determinations of Mr. Lesquereux be correct,* it is evident from the above that the vegetable life of North America reached its present condition one epoch or period earlier than the higher Vertebrata, and that the nomenclature is thus thrown back by so much It would appear that the recent flora of North America is a period older than the fauna, i. e., has persisted longer than the latter by a certain length of geologic time. Applying the same reasoning to the past, I embodied the idea in reference to the Laramie period ("Fort Union") in the statement that "a Cretaceous fauna was then contemporary with a Tertiary flora" ;t and, later, that "an Eocene fauna was contemporary with a ^Miocene flora." It may have to be added that a Miocene fauna was contemporary with a Pliocene flora. Since Mr. Lesquereux has the support of the best paleobotonists of Europe in his conclusions, it is useless to take the ground assumed by a few of my colleagues, that the former gentleman has simply erred in his determina- tions. He gives us grounds for believing that he has not done so, by giving us the European standard by which his identifications are governed.^ It is as follows : Pliocene .. Miocene .. Oligocene . Eocene ... Paleocone. Lower limits not positively fixed; largely developed in Italy, t (Subapennine, E.D.C.) Ocningian; Mayencian; Aquitanian. Tongrian. Gypso of Aix ; Alum Bay ; Mt. Bolca ; London Clay ; Sheppey ; Oris of the Sarthe. Upper Landcnian; Sezanne (=:Panisclian). Sueawnian (Lignitio Soissonais; Sables de Bracbeux); Lower Landenian. Horsian; Gelindon. ^Limestone of Mens, overlying nnconformably the Maestriohtion. • The above parallels are well presented by Dr. Pealo in his report to Dr. Haydcn, Ann. Kept. U. 8. Geol. Surv. Terra. 1S7J, p. Ill ct tcq. t Bulletin U. S. Ocol. Surv. Terra. I, art. 2. p. 16, April, 1S74 (Ann. Beport U. 8. Geol. Surv. Terrs. Ib74, p.aS5. PEIMITIVE CHARACTERS. 45 This system, it will be observed, is almost exactly identical with that employed in the preceding pages as the standard of comparison for the Vertebrata. Yet it has resulted, from a most careful comparison of both faunae and florae of America with this standard scale, that two distinct paleontological series have to be adopted, the one for the vertebrate life and the other for the plants, of the Western Continent. If this result be accurate, and there appears to be no avoiding it, an explanation must be sought. There are only two possible ones ; either the animal life of North America has lagged behind that of Europe by one period during past geo- logic time ; or, secondly, the vegetable life of America has been equally in advance of that of Europe during the same period. In other words, if the plant-life of the continents was contemporaneous, ancient types of animals remained a period longer in North America than in Erope. If animal life was contemporaneous, plant-life had advanced by one period in Europe beyond that which it had attained in North America. In any case, either the faunal or the floral standard of estimation of geologic age of strata for North America is a false one, since there can be but one standard of com- parison for anything. But this great fact being understood, the evidence of each of the great departments of life possesses its own intrinsic value. In conclusion, it may be observed that the lacunae in the series as pre- sented by one continent, render us dependent on the other for the evidence necessary for the complete elucidation of the laws of the creation of animal life. Phylogenies can be thus constructed which would otherwise be impos- sible, and the results of researches into the earliest types of Vertebrata become intelligible. Thus I have been able to prove, in support of a thesis published in 1874, that the earliest Ungulate Mammalia were pentadactyle and plantigrade. I have also shown that the ankle-joint had not, in the primitive Mammalia, the hinge-like character that it has in the later ones, but that it is without the interlocking superior articulation. The small size of the brain of early Mammalia, already pointed out by Lartet, has received extensive confirmation by the researches of Marsh, who has also shown the progressive increase in size of the whole body in various mammalian lines. To these results I have added another, which is derived from the study of numerous Permian Vertebrata, viz, that the earliest land vertebrates had a persistent chorda dorsalis. PART FIRST. THE PUERCO, WASATCH, AND BRIDGER FAUNA 47 P^RT FIRST. THE WASATCH AND BRIDGER FAUN^. PISCES. The remains of fishes are abundant in the lacustrine Eocene forma- tions of the United States, and several principal groups are represented. These pertain to the Elasmohrancld and the Hyopomata ; Dipnoi and Holoce- phali are unknown. Of Hyopomatous fishes, indications of the Crossop- terygia and the Chondrostei have not yet been found, but of the third group, the Actinopteri, we have several distinct orders, commencing with the more generalized Ginglymodi and ending with the specialized Percomorphi. The facies of the Eocene fish fauna is that of the existing fresh waters of the United States, exclusive of the great order of the Plectospondyli (unless the Amyzon beds are Eocene), and with the addition of two families, Osteoglos- sidee and Chromididee (aff*.), at present confined to the southern hemisphere. ELA8M0BRANCHL XIPHOTRYGON Cope. American Naturalist, 1879, p. 333. Family Trygonidce; that is, the tail furnished with a seiTate spine and the pectoral fins united in front of the rostral cartilage. Teeth closely placed in a few rows, the crowns developed into a triangular cusp, which is directed backwards, as in Raja. Pelvic arch without anteriorly directed inferior processes. No superficial ossification of the rostral cartilage. No caudal fins observed. This genus is Trygon, with the teeth of Raja. It further differs strik- 4 49 50 TUE WASATCH AXl; iiUlDGEK FAUNiE. ingly from tlie typical Tnjgones in the form of the caudal spines. These are trigonal in section, ami l)ear a ventral keel, and a serrate edge on each side. The extinct species of the Monte Bolca Eocene, Trygon muricata, has, according to Gazzola, the spine of the true Trygones. XlPHOTRYGON ACUTIDENS CopC. American Naturalist, May, 1879 (April). Plato I, figs. 1-5. This species is of graceful proportions, having no great transverse expansion, and possessing a long and slender tail. The size is inferior to that of a fully-grown skate, but much exceeds that of the Cyclohatis oligo- dactylus of the Lebanon. The ossification of the superficial part of the cranial cartilage is wide, extending to the branchial fissures below. It terminates anteriorly, in a sliglitly concave truncation, a short distance in front of the orbital open- ings. Two convex lobes immediately behind the mouth, divided by a median fissure, resemble the labial flaps. They are marked by rather larger hexagons than the other surface. The least hexagons form a longi- tudinal oval patch on the middle line behind these flaps, which corresponds in position to the superior fontanelle. Posterior to the scapular arch the ossification forms a band on each side of the vertebral column, and, gradu- ally narrowing, disappears near the origin of the caudal spines. The proptervgia extend well forward, giving outline to an acute snout. They are segmented to the extremity. The outline of the fin expands gradually from this apex. The metapterygial border is very stout, and is not so long as the propterygial. The posterior border of the pectoral fin does not extend quite so far posteriorly as the posterior border of the ven- tral fin. The latter, in turn, extends for about three-fourths the length of the claspers from the base of the fin. Pectoral rays; metapterygial, 31; mcsopterygial, 10; propterygiiil, 41. The vertebra^ are fully ossified; the caudal series becomes very slender distally, and measures nearly twice as long as from the pehac arch to the anterior border of the cephalic ossification. In the specimen described there are three caudal spines situated near together, whose origins are a ELASMOBEANCHI. 51 little posterior to the middle of the length of the caudal series of vertebrae. They are all depressed at the base and triangular in section beyond, and have an acute ventral edge. The lateral edges are finely and rather remotely serrate, the serration being obsolete on the smallest or anterior spine. In all, the infero-lateral faces of the spine form a shallow groove, like that of a bayonet. These spines are very different from those of the Trygons of the American and European seas, where they are depressed, oval in section, and have the teeth on each side much more closely placed. The teeth of this species are small. Viewed from below, those of the upper jaw form a very few series of triangles, with their bases approxi- mated and their acute apices directed backwards. Their bases are of differ- ent form, and are expanded and probably bifurcate, as several sections or anterior views of teeth are preserved, which exhibit two divergent roots and a flat summit. The functional surfaces of the triangular crowns are flat. The greater number of the segments of the fin-rays are shown by the sections to have been hollow cylinders, with a fibrous axis Measurements. M. Total length (entire) 515 Total width at middle of abdomen 230 Length of head (without muzzle) to scapular arch above 100 Length of abdomen to pehdo arch 064 Length of tail 351 Length to origin of spine ICO Length of spine 040 Depth of spine 003 Width of base of muzzle .' 023 Width between propterygia (greatest) 060 Width between metapterygia (greatest) '. 065 Width of pelvic arch iu front - 043 This species is so far known to me from a single specimen. This was obtained from Twin Creek, in the Bear River region of Southwestern Wyoming, by Leslie A. Lee, of Bowdoin College, Maine, who very liber- ally placed it at my disposal for study and description. Its presence in the Green River shales, adds to the evidence offered by other anadromous types of fishes, in favor of the view that the Green River Lake had commvinication with the ocean. The first information as to the existence of rays in the Green River formation was furnished by Professor Marsh, who obtained a specimen from 52 Tnr. wasatch and BRrooER faun^. Twin Creek. He gave .a meager description of the species, but quite neg- lected to describe the genus, on which account its affinities remain unknown. The presence of several tubercles mentioned by Marsh indicates that it is a different species at least from the Xiphotryyon acutidens. GINGLYMODL Cope, Proceedings American Association for tbe Advancement of Science, 1H71, p. 330. Physostomous Actinopteri, with a praecoracoid arch and a coronoid bone of the mandible. Vertebral centra opisthocoelous. Parietal bones in contact ; pterotic and opisthotic bones absent ; pectoral fin with mesoptery- gium and five other basal elements This order contains as yet but one family, the Lepklosteklce, which em- braces three genera, the recent Litliolepis and Lepidosteus, and the extinct Clastes. The existing species, as is well known, are confined to the rivers and lakes of North America, while the extinct forms occur in both Europe and North Ameiica. The earliest appearance of this type in geological history yet known was in the Laramie or Upper Cretaceous epoch in North America. Individuals of one species, Clastes occidentalis Leidy, were very numerous at that period. During the Wasatch or Suessonian in North America, they were equally abundant, and I have described two species from this honzon in New Mexico. Species and individuals are plentiful in the Bridger beds, as indicated in the following pages, but in the various tracts of the White River epoch they are absolutely wanting.* Tliey do not occur in the Loup River deposits east of the Rocky Mountains, and only reappear in the interior of the Continent in the present period. On the other hand, the family is represented in the marine Miocene beds of the Atlantic seaboard by the genus Pneumatosteus Cope, of which a single speciesf has been foimd in North Carolina In Europe tlie Lepidosteidce make their appearance at nearly the same horizon as in America, Lemoine having obtained Clastes from the lowest Suessonian (Chalons-Sur-Vesle), and Gervais having determined it from the Upper Suessonian. * ProcecdiniKS Aiiu'rican Pliiloso]iliiciil Socioty, 1877, p. 9. t Proceedings Americau I'bilusoiiliical Society, 1669, p. 242. GINGLYMODI. 53 CLASTES Cope. Annual Report U. S. Geol. Surv. Terrs., 1872 (187.3), p. 633. American Naturalist, 1878, p. 761. Mandibular ramus, without or with reduced fissure of the dental for- amen, and without the groove continuous with it found in Lepidosteus. One series of large teeth, with small ones exterior to them in the dentary bone, the inner superior aspect of that bone without prominent dentiferous or rugose rib. An inspection of French specimens, probably belonging to this genus, has shown that the maxillary bone is much less segmented than in Lepidos- teus, if it be divided at all. The characters o£ Clastes were originally derived from the under jaw, and I have observed them in two species, one which I suppose to be the Lepidostens gldber Marsh, and the other L. atrox Leidy. Tlie species of this genus resemble in many ways the Lepidostei of the present day. Their scales are rhombic and pierced by a duct on the lateral line. The cranial bones are ornamented by tubercles of ganoine, distrib- uted variously, according to the species. Some of these fishes reached a large size, exceeding any now living, othei's resemble the true Lepidostei in this respect. The first indication of the occurrence of gars in our Western Tertiaries was furnished by Professor Marsh, who announced his discovery of them before the Academy of Philadelphia (Proceedings 1871, p. 105). He named two species, but did not give any descriptions, excepting so far as the statement that one of them has "unusually short vertebrae," and that the other has them " proportionally longer," maybe regarded as such. Under these circumstances I have been unable to identify the species referred to, and think that the names proposed for them by Marsh cannot be used. Clastes anax Cope. Annual Eeport U. S. Geol. Sui-v. Terrs., 1872 (1873), p. 633. Plate II, figs. 50-52. Represented by some cranial bones and especially by a post-temporal, which indicate a very large species of gar, two or three times as large as the alligator gar of the Mississippi, (Litholepis ferox). The bone has a 54 THE WASATCH AND RRIDGER FAUX^^. free, ovate posterior outline, and its superior surface is covered with a thick layer of dense bone, which has not the brilliant surface of ganoine. This substance is thrown into elevated, coiTugated ridges, which are generally transverse to the long axis of the bone, and inosculate and are interrupted frequently. The spaces between are as wide as the bases of the ridges. Measurements. u. Width of bone 042 Thickness of bone 012 Found in the Bridger bad lands of Ham's Fork, Wyoming. Clastes atrox Leidy. Cope, Annual Report U. S. Geol. Surv. Terrs., 634, 1872 (1873). Lepidosteus atrox Leidy, Proc. Acad. Nat. Sci. Phila., 1873,97. — Report U. S. Geol. Snrv. Terw., i, 1873, p. 189, PI. x.\xii, tigs. 14-15. Abundant, and represented by both rough and smooth scales, the former from the anterior part of the body. As this species has been already described by Leidy, I only refer to my Plate II, figs. 1-24. Clastes cyclifeeus Cope. Annual Report; U. S. Geol. Surv. Terra., 1872 (1873), p. 634. Plate II, figs. 25-45. Established on numerous remains of a small species, in which the scales are rather wide, and generally with obtuse extremital angles, and frequently in certain regions of the body entirely rounded at the posterior border. Fragments of the cranial bones are ornamented with scattered tubercles of ganoine of rounded form, and not distributed in lines as in some species. In a fragment from the posterior part of the mandible, there is a single row of large teeth, with a series of minute ones between them on the outer edge of the bone. The external face presents a smooth, superior surface, and a rugose inferior portion which is marked by irregular lines of points of ganoine. Measuremeiits, M. Depth of dentary bone WCO Width of above 00,\5 L<'iiKt)i of a Hcalc (exposed face) OOGO Width of a scale (exposed face) OOtX) From the Mammoth Buttes, Washakie Basin. GDfGLTMODI. 55 Clastes cuneatus Cope. Proceedings American Philosophical Society, 1877, p. 9; (name only). Plate I, fig. 6. This gar is represented by numerous specimens from the Manti Shales of Central Utah, some of which are preserved almost entii-e. None of them exceed a foot in length. I describe the best specimen accessible to me, a small one, kindly lent me through Dr. Hayden by Mr. Bai-foot, director of the museum of Salt Lake City. The proportions are rather stout, and the base of the ventral fin is a little nearer the base of the tail than the end of the snout. The head is not perfectly preserved, but its outline, as clearly defined on the slab of limestone, is wedge-shaped, not longer than in Lepidosteus platystomus, but narrower. This view is, however, partly profile. The posterior and infe- rior borders of the operculum form a continuous segment of a circle, and the depth of the suboperculum is .66 the horizontal width of the opercu- lum. The preoperculum is superficially divided by transverse grooves into four scuta, of which the superior is the largest ; they are ornamented with small tubercles of ganoine. All the other bones, includirig the frontals, present radiating lines of the tubercles which are capped with ganoine, excepting on the operculum and suboperculum, where they form scarcely interrupted ridges. The scales are smooth, even near the scapular arch, and are arranged in eighteen or nineteen longitudinal series, as seen in an oblique row directed obliquely upward from the ventral fin. Fulcra of the ventral fin rather long and slender. The region of the dorsal fin is some- what disturbed; the fin is in any case situated very far posteriorly; anal and extremity of caudal fins wanting. Measurements. M. Axial length from end of mnzzle to base of caudal fin 215 Axial length from end of muzzle to base of dorsal fin 182 Axial length from end of muzzle to base of central fin 125 Axial length from end of muzzle to edge of operculum 063 Length of skull to preopercular border .049 Depth of skuU at preopercular border 036 Depth of body at ventral fin 050 56 THE WASATCH AND BRIDGER FAUN^. This species differs from some of those of the Bridger formation in the smoothness of the scales on the anterior part of the body. It is a smaller species than most of those of both that formation and the Wasatch. The characteristic vertebrie are e.xhibited by various specimens. HALECOMORPHL PAPPICHTHYS Cope. Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 634. Family Ami'uJce. Vertebrae short, the abdominal with prominent dia- pophyses, and with each neurapophysis articulating with two centi'a; sides of the centrum not pitted. Maxillary bone supporting a single series of teeth and with a supplementary bone on its distal upper border. Dentary bone deeply grooved on the inner side and with but one series of teeth. Surface of cranial bones sculptured. This genus differs from the existing Amia in the presence of only one series of teeth instead of several, on the bones about the mouth. The ver- tebral centra possess a smaller anteroposterior diameter and relatively greater transverse diameter in the anterior part of the column ; but the value of these characters is not yet certainly understood. The maxillary bone overlaps the premaxillary extensively by its proxi- mal extremity, and presents no condylar facets (P. pUcatus). The sym- physis of the dentaries is not sutural. The condyle of the inferior quadrate is rough (P. leevis, P.plicatus). Its posterior grooves show the position of a symplectic ; while the inferior anterior portion shows a coarse sutural ser- rate junction with the ectopterygoid (in the above species). The centra of the vertebrae are most transverse anteriorly; in the posterior abdominal region they become subround; in the anterior caudal region, higher than wide; and in the greater part of the notocaudal region are subround They all have a minute notochordal performation. The neurapophysial facets of the anterior and posterior positions are distinct in the anterior abdominal ver- tebrae, and confluent on the caudals of all the species; the point at which they become confluent is different in the different species. On a few ante- rior abdominal centra the inferior surface is entire, or displays a slight depression; soon two parallel fissures, one on each side of the median line, HALECOMOEPHI. 57 appear, which become oblong fossae. These continue until they become naiTOwed again, anterior to the caudal senes. In the latter they are as well developed as the neurapophysial pits and are much like them. Several species of this genus have been found in the Bridger forma- tion in "Wyoming and Colorado, but it does not occur in the Wasatch. While some of them were first reported by Marsh, who referred them to Amia, they were first described by Leidy (Report U. S Geol. Surv. 4to Tol, I., p. 184, Plate xxxviii). One generic and one subgeneric names were used by Dr. Leidy in this connection, but without diagnoses. Among the specimens at my disposal I have found but one genus, to which I gave the name now used, with a characteristic diagnosis This genus is the earliest known representative of the order Haleco- morpM, which consists at present of but two genera; the present one and Amia. The latter first appears in America in the ? Eocene Amyzon shales of Florissant in the South Park of Colorado, where two species have been found; A. seutata Cope, and A. reticulata Cope.* Pappichthys first occurs in the Bridger formation, and constitutes one of the faunal distinc- tions between that epoch and the Wasatch, which immediately preceded it. However, it occurs in the Wind River beds, mixed with Wasatch Mammals. In Europe this genus is found at lower horizons than in America, having "been discovered by Dr. Lemoinef near Reims, in the Suessonian conglomer- ate, which answers partly to the lowest Wasatch and partly to the Upper Laramie epochs. Pappichthys sclerops Cope. Annual Report U. S. Geol. Surv. Terrs., 1672 (1873), p. 635. Plate III, fig. 1. Established on a ramus of the mandible of one, and other similar specimens of other individuals. These indicate a large fish, equal in size to the alligator gar of the Mississippi. The dentary bone is more compressed and deeper than in P. plicatus. The longitudinal groove runs above the mid- dle line, and the poition of the bone below it thins to an edge. The upper portion is thickened, and the alveolar border is wide and bounded by an angle * Se« Bulletin of tbe U. S. Geol. Surv. Terrs , 1875, p. 1. t Kecherclics s. 1. Oiseaux Foss. Tert. Infer, des En v. Reims, 1378, p. 65. 58 THE WASATCH AND lUMDGER FAUN^,. on the inner side. The alveoli are large and shallow; in .t»25 m. scarcely three find place. Near the symphysis is a smaller one \\ hit li is separated by a considerable diastema from the succeeding one (perhaps abnormally). The external face of the bone is rough and somewhat tubercular. Measurements. M. Duptli iif (Irntary at Byin|ih,v8iti OiJ3 Depth of ilfiitary at middle - 036 Depth of dentary at elcveiitli tooth 048 Tbickuess of dentary at eighth tooth 018 Pappichthys LiEvis Copc. Auuual Keport U. S Geol. Surv. Terrs., 1872 (1873), p. 636. Plate lU, figs. 2-11. Represented by various fragments, including dentary and vertebral bones. The former differs from that of the species just described in the smaller .size of its teeth, there being six in a space occupied by but four in it, at a point where the dentaries have equal depth. In other words, there are four in .0250 m. The alveolar face is also much more oblique, being in fact continuous with the inner face of the bone. The external face of the dentary is smooth and thus different from that of P. sderops. The pre- maxillary bones of opposite sides are not coossified with each other, and they are narrowed fore and aft at their anterior suture. The posterior side of the distal half of the bone is beveled for the anterior process of the maxillary. Its alveolar face is marked for the bases of six teeth. The pos- terior face of the inferior quadrate shows the symplectic to have been a large bone, and to have descended nearly to the condyle of the former. Some fragments of the top of the skull show that it was roughened with low, obtuse ribs and lines. A dorsal vertebra is but little wider than deep and is truncate below, presenting a prominent infero-lateral angle. Measurements. H. Depth of dentary near middle 0:f7 ThiekiiesM of denlury near middle 01'2 Depth of eentnim of vertcl)ra (l*.?9 Width of otntnim of V(rt"^. This order, so extensively developed in recent times, first appears in geological history in a single genus in the Bridger Eocene. It has not yet been found at a lower horizon than this. These earliest forms do not differ widely from recent ones, so far as appears. RIIINEASTES Cope. Procced.Amer. Pbilos. Soc.,1872, p. 486 (published August 20, 1872). Annual Beport U. S. Geol. Surv. Terrs., 1872 (1873), p. 638. This genus differs from those at present inhabiting North America in the presence of teeth on the vomer (B. cdlvus). The teeth are everywhere coarsely villiform. The occipital bone exhibits a pit on the middle line below, and a surface for attachment for the inferior branch of the post-tem- poral on each side {JR. calviis, B. smithii). The modified anterior vertebrae mass is deeply grooved below {B. smithii). The cranium is covered with a rugose exostosis {B. peUatus, B. calvus, B. smithii), and has a strong closed groove in the position of the usual fronto-parietal fontanelle. The verte- brae (B. smithii) are short, and the sides of the centi'a only striate with the circumference. There are no lateral pits, but a pair above and a pair below, with a coossified apophysis at the base of one of them. The spines preserved belong chiefly to the pectoral fin. They are strongly striate and weakly dentate, and have the usual hinge with superior recurved flange above, and two embracing processes below at the base. The dorsal spine is weaker in B calvus, but strong in B. peltatits. In the former species it stands on the transversel}' expanded summit of the intert neural bone, which presents a median process upwards and an articular face on each side upwards and backwards. The median process is divided from above, and the excavation receives a subglobular enlargement of the middle of the base of the spine. This, with the two lateral facets of the basal expansions of the spine, constitute the hinge on which the latter moves. This genus differs from those at present inhabiting the fresh waters of North America, not only in the presence of vomerine teeth, but also in the exostosis of the superior and lateral surfaces of the skull. The anterior part of the cranium being absent from my specimens, I am not able to determine whether Bhineastes should be referred to the Pimehdina or the NEMATOGXATHI. 63 Ariina of Giinther's system. In the former case the genus resembles the Phractocephalus or the Piranmtana. In the latter case it will fall into the immediate neighborhood of Arius. These three genera are at present existing in South America, so that it appears that the Nematognatld of the Eocene of the Rocky Mountains present the same neotropical resemblances to be traced in the Dajjedoglossus and Priscacara. M}^ expedition obtained remains of four or five species of this genus from the Bridger beds, and one from the Amyzon beds of Colorado; but none have as yet been discovered in the shales of the Green River formation. The species are distinguished as follows : I. Rhineastes ; a large, massive iiucbal shield. Cepbalic o.ssificatiou pappilliforiu B. peltatus. II. Astephus; nuchal shield uarrow and short. Cephalic ossification in smooth lines; one basiocciijital pit; pectoral spines serrate on both edges B. smithii. Three basioccipital i)its; pectoral spines serrate on both edges B. calvus. Pectoral spiues serrate behind only; curved B.Mrcvatus, The cephalic bones of the B. arcuatus are unknown. Rhineastes peltatus Cope. Proceedings American Philosophical Society, 1872, 486. Plate V, figs. 1-2. Established on cranial and other bones with spines of a siluriform fish of the size of, perhaps, the Amiiinis lopli'ms. The form and the excessive rugosity of the external bony surfaces, reminds one of some of the Brazilian Dorades. The frontal fontanelle is closed, though very distinctly marked by a deep groove, with its fundus smooth. The rugosity consists of innu- merable well distinguished osseous papillae. The cranial ossification is con- tinued posteriori}' as a shield, which is strongl}^ convex from side to side. The spine is symmetrical and probably dorsal. It is compressed and curved antero-posteriorly, and is deeply grooved behind Laterally it is closely striate-grooved; the anterior face is narrowed, obtuse, and minutely serrate, with cross ridges; each side of it is rugose, with several irregular series of pronounced tubercles arranged transversely. 64 THE WASATCH AND BRIDGEE FAUN^. Measurements. X. Width frontal bono near firont of fontanelle 0.012 Thickness at same point 004 Thickness of casque 004 Width spine 005 Depth spine 009 The single individual of this species whose remains are preserved shows that it was the most robust, though not the largest of the genus. I found it on South Bitter Creek in the Washakie basin of the Bridger forma- tion. Rhineastes SMiTHii Cope. Proceed. Amer. Philos. Soc., 1872, p. 486 (August 20). Annual Report U. S. Qeol. Snr\-. Terrs., 1872, p. C39 (1873). Plate V, figs. 5-11. Represented by remains of several individuals, including one with vertebrae, basioccipital, opercular and other cranial bones, with spines. They indicate a fish of the size of the large catfishes of the Ohio River. The pectoral spines are quite compressed and distinctly striate-grooved on the sides. The posterior groove is occupied by short, spaced, recurved teeth ; the anterior by an acute edge, bounded by a gi-oove on each side, which has a fine, close serration. The surface of the modified vertebral mass is sti'iate ridged ; that of the basioccipital still more strongly ridged. In the latter there is a median pit behind, and the points of attachment of the inferior limb of the post-temporal is in front of it, smooth, and without reverted edges. The operculum has a large compressed, sessile cup, and its external .surface is strongly ridged and grooved, radiating from above in front. Measurements u. Diameter of a vertebra 021 Length of centrum 009 Diameter of moditicd vertelirn 013 Diameter of groo vo of vertebra 005 Diameter of occipital articulation 015 Length of cup of operculum 013 Diiimeler of spine at base 008 Diameter of spine at .004 from base 0037 Another pectoral spine is larger; diameter at base .010. From the Mammoth Buttes and Laclede, on South Bitter Creek.* • Named for my respected friend, Daniel B. Smith, of Gerraantown, Philadelphia, many years principal of Haverfurd College, ond a student and lover of natural sciences. NEMATOGNATHI. 65 Rhineastes calvus Cope. Annnal Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 640. Plate V, figs. 3-4. Represented by several specimens, including most parts of the cranium, spines, etc. One of these shows the supraoccipital production to have the form of an equilateral triangle, with a sinus of the posterior border on each side of it, which advances in front of the epiotic bone below. Shortly in front of this point the deep groove representing the fontanelle commences. The cranial rugae are lines parallel to the fontanelle, which diverge to the margins of the occipital prolongation, and are frequently connected by cross-ridges. The frontal portion of the skull is much expanded laterally, and the part beneath inclosed by the prefrontals, particularly wide. The fontanelle in this region does not appear to have been entirely closed. The surface is here also strongly rugose. The vomer has a T-shaped anterior extremity, which is immediately followed by two transverse paral- lelogrammic patches of premaxillary brush-teeth in several rows. They are about twice as long as wide, and in contact medially. The anterior margin of the premaxilla projects their length beyond them, and is perfectly smooth, and has a smooth, rounded border. The basioccipital has a sub- cordate cotylus. In front of the median inferior pit are three groove-pits ; the articular face for the post-temporal is opposite the former and is rugose and has strongly reverted edges. Measurementg. M. Diameter occipital articulation DOBS' Diameter base supraoccipital shield 0130 Width front above orbits 0043 Length from vomer to premaxillary border 0110 Length of both tooth patches 0120 Diameter pectoral spine at base 0031 The pectoral spine is seiTate on both edges. The base of the dorsal is symmetrical and articulates with its intemeural bone by two lateral flat, and one convex median anterior surfaces, whose surfaces are curiously rugose. The intemeural has a rugose median superior keel, which termi- nates in a point which is received into a pit of the base of the spine ; there 5 o 66 THE WASATCH AND BEIDGER FAUN^. is a similar production on the posterior side for a similar purpose. The basis of the spine proper is smaller than that of the pectoral, and is about as wide as deep. In a number of fragments of another indi\ndual found together, the basioccipital has the characters already described. The dentary bone is curved inward, and is acute below, widening regularly to the alveolar border. There is no groove on the inner face, while the outer is striate- grooved and has a series of pits along its lower middle. Measurements. It Diameter occipital articnlation 009 Width alveolar face. 004 Depth ramus at middle 008 A part of the operculum of a third individual (with similar spines) displays great rugosity and elevated radiating ridges; length of articular cup ".OOGS. The specimens are chiefly from the bad lands of the Upper Green River. Rhineastes aecuatus Cope. Plata V, fig. 12. Annnal Report U. 8. Geol. Snrv. Terra., I^f72 (1873), p. C41. Pimelodus antiquus Leidy, Final Report IT. S. Geol. Siirv. Terw., i, 1873, p. 193, PI. xvii, figs. 9, 10. Proceedings Academy Phila., 1873, p. 99, name only. There are numerous spines about the size of those of the last species, which differ in the want of the fine serrated anterior edge. I select one aa the type, wliich belonged to the pectoral fin of the right side. It is unbroken, and is curved from base to apex. The latter is acute by an oblique posterior truncation. The surface is strongly striate and the teeth of the posterior edge are closely set ; the proximal point distally, the distal proxiniall}-. In this specimen there is a trace of anterior serration ; in many specimens none whatever. The external surfaces of the epiclavicular and coracoid bones are strongly rugose-striate, as is the case in all the species of this genus, and the most characteristic fragment is that portion of the scapular arch at the base of the pectoral spine. Measurements. u. Length of Hpinc on riin'c 052 Dianii'tcr at liane; long 006 Diameter at banc ; iihort 004 ISOSPONDYLI. 67 The recurved plate of the base is rugose as in other catfishes. The spines themselves are less compressed than in B. calvus. It is probable that the name applied by Dr. Leidy to this species was published a short time before my own, but as it was not accompanied by a description it cannot be used. From the Bridger beds of the Upper Green River. ? Rhineastes radulus Cope. Annual Report U. S. Geol. Siirv. Terrs., 1372 (1873), p. 639. Plate V, figs. 14-17. This species rests on a number of broken cranial bones. I referred it fonnerly to this genus, but now regard the reference as purely provisional. It is likely that it does not belong to BJiineastes, but what its proper generic position is, I am not at present able to determine. The cranial bones pi'esent a pattern of exostosis quite distinct from that observed in the known species of Rhineastes. This consists of closely placed crenate ridges, which radiate from various points, and are sometimes broken up, but always rough or serrate on the edges. The bones are not so thick as in the R. peltatus; i. e., .0025 m. - ' From bad lands of Cottonwood Creek, Wyoming. ISOSPONDYLI. Cope, Proceedings American Association for the Advancement of Science, 1871, p. 33. Actinopterous fishes with physostomous characters, having the scapular arch suspended to the cranium; a praecoracoid arch, and a symplectic bone, but no coronoid bone, and with the anterior vertebrae unmodified and with- out ossicula auditus. Two families of this order are represented in the Green River and Bridger beds by numerous individuals. These are the OsteoglossideB and the Clupeidce, which are distinguished by the following characters of the skeleton : Tail, homocercal; pterotic bone, normal; basis cranii, double; superior pharyngeals four, distinct, third largest and directed forwards; basal bran- chihyals three; parietals separated by supraoccipital; one vertebra included 68 THE WASATCH A^TD BRIDGER FAUNJ3. in the caudal fin. (Psuedobranchite and pyloric appendages). Clupeidth at middle anal ray 027 Depth at base of caudal tin 016 This Herring is repi'esented by a great number of well-preserved spec- imens, and was, next to the Z>. humilis, the most abundant fish of the waters of the ancient Green River Lake basin. It is distinguished from the D. dentatus by the large number of anal and smaller number of dorsal radii, and by the shorter head and relatively more slender body. The specimen measured represents the average size; the largest obtained is half as large Again, and much smaller than the type of D. dentatus. From Twin Creek, Wyoming. DiPLOMYSTUS PECTOEOSU8 CopO. Bulletin U. 8. Geol. Surv. Terrs., 1877, p. 810. Plat* X, fig. 3. This Clupeoid is represented by small specimens of a deeper form than that seen in the two preceding species. It is also characterized by a smaller number of dorsal radii than either of them. Formula: D. I. 8-9; A. I. 40-44. VertebriB: dorsal, 16-17; caudal, 22. The greatest depth is in the pectoral region, and enters the length minus the caudal fin a little less than three times. The outlines contract from the ventral fins, and the anal region is longer than the abdominal. The eye is a little more than one- fourth the length of the head, and the latter enters the total minus the ■caudal fin three and a half times. The ventral fins are small, and commence well in advance of the line of the dorsal. The last dorsal ray is nearly above the first anal ; the caudal is deeply forked. As in the two preceding species, the neural spines in front of the interneurals present a laminar antero-posterior expansion. The dorsal scuta are furnished in the D.pectoro- 3US with an especially prominent median keel. ISOSPONDYLI. IT Measurements. u. Total length 090- Length (axial) to below D. 1 038 Length (axial) to above A. 1 043 Length (axial) to base of caudal fin 070 Length of head 022 Depth at orbit OIT Depth at pectoral fin 026 Depth at dorsal fin 024 Depth at caudal peduncle 008 r This species is represented by several specimens, from Twin Creek Wyoming. DiPLOMYSTUS THETA Cope. Bulletin U. S. Geol. Surv. Terrs., 1877, p. 811. Clupea iheta Cope, Annual Report U. S. Geol. Surv. Terrs., 1873, p. 461. Represented by a specimen from the Green River shales near the mouth of Labarge Creek, in the upper valley of Green River. It is a larger species than the C. Immilis Leidy, which is also found at the same locality, and it has much longer anal fin. Its radii number 26, possibly a few more, as the end appears to have been injured. The dorsal fin is short; the last ray in advance of the line of the first of the anal. The body is deep. Number of vertebrae fi-om the first interneural spine to the last interhsemal, 29. Depth at first dorsal ray, .04«5; depth at last anal ray, .0170; length of 29 ver^ tebrae, .0780. The posterior part of the body having been lost, the number of anal rays is unknown. It is quite possible that further investigation may show that the -D. analis is identical with this species. DiPLOMYSTUS HUMiLis Leidy. Proceed. Acad. Phila., 1856, p. 256. Final Report U. S. Geol. Surv. Terrs, i., p. 195, Plate xvii, fig. 1. Clupea 2>wiUa Cope, Proceed. Amer. Philos. Soc, 1870, p. 382. Annual Report U. S. Geol. Surv. TeiTS., 1870, p. 429. Plate rx, fig. 8; Plate X, fig. 4. This and the following species, already referred to a distinct section of the genus Liplomystus, difi'er from those above described in several points. They have a much shorter anal fin, and the caudal part of the vertebral column is thus shorter. The anterior neural spines do not present the antero-posterior laminar expansion. The ventral fin commences a little 78 THE WASATCH AND BRIDGER FAUNiE. behind the origin of the dorsal. The formulae for the D. humilis are as fol- lows:— Radii: D.I— 11; A. I— 14. Vertebrtv: D. 21; C. 13. Depth to length as 3 : 8. 5. Specimens of this fish are equally abundant at the Green River and Twin Creek localities. A rather small specimen from the former place was described by me as the type of another species, but I think it represents merely a young individual. When I described it I was under the impres- sion that the D. alius was the true D. humilis of I.,eidy. This view was justified by Dr. Leidy's description of the D. humilis, where the measure- ments given are those of the B. alius. The figures given (3J inches long by 16 lines deep) are, however, partly erroneous, as they do not agree with those subsequently given, nor with the plate above cited. The description of a Green River specimen is as follows: Greatest depth contained four times in the total length or 3.5 times to basis of caudal fin. Length of head 3.2 to basis caudal. This measure- ment may require revision, as the end of the muzzle is slightly injured. Orbit large, contained twice in length of head behind it. Middle of dorsal fin near the middle of the length, and about over the origins of the ventrals. D. II, 1 1, V. 7. Pectoral extending half way to ventrals. Vertebrae, 2!)-30; dorsals, 16-20. Ventral keeled ribs, 18. Anal fin lost. Caudal peduncle slender caudal fin deeply furcate. Length, ".044; greatest depth, "Oil. A second specimen exhibits the characters of the species more dis- tinctly in some respects. There are 30 vertebrae, of which 13-14 are caudaL The general shape is regularly fusiform, and the head rather acuminate. ' Measurements. H. Total length 054 Lc;nj;th to preopercnlar edge 01 Li'iinlli to opercular edge 013 L«iiglli to posterior margin dorsal (H55 Length to anterior margin anal .034 Length to Iibho lauilal 044 Depth at oroiput .011 Dejith at middle of dorsal 0116 Depth nt caadal peduncle '. 0046 The largest specimen of this species which I possess is "150 in length. PEECOMOKPHI. 79 As at the Green River locality, so at Twin Creek, this Herring is the most abundant species One-third the entire number of specimens are referable to it. DiPLOMYSTUS ALTus Leidy. Cope, Bulletin U. S. Geol. Siirv. Terrs., 1877, p. 811. Clupea alta Leidy. Final Eeport U. S. GeoL Snrv. Terrs., i, p. 196 Plate XVII, fig. 2. This small Herring is abundant in the Green River shales, both at Green River and at Twin Creek. It is distinguished from the D. humilis by the greater relative depth of the body, resembHng in this respect the D. pectorosus. The difference which it presents in this respect is rather too great to permit its union with D. humilis. Nevertheless intermediate speci- mens occur, but their characters are sometimes found to be due to distortion. Formulge:— Radii: D. I. 11; A. 1. 13-15. Vertebra: D. 22; C. 12. Depth to length (without caudal tin) as 4 to 8. Size that of the D. humilis. PERCOMORPHl. Cope, Proceedings American Association for the Advancement of Science, 1671, p. 341. Physoclystous Actinopteri, with the shoulder-girdle attached to the skull, and thoracic or jugular ventral fins. Maxillary and dentary bones distinct; cranium symmetrical; epiotics normal; no interclavicles ; post- temporal not coossified with cranium. Basal pectoral radii not enlarged ; femora suspended (generally) from the scapular arch. Basibranchials thi-ee; superior pharyngeals with the third usually the largest; sub and interoper- culum present, plate-like. Three families are represented in the Eocene Tertiary beds, two of which certainly belong to this order, and the third very doubtfully. The former are the Percidce and IPomacentridcB, representing the suborders Distegi and Pharyngognathi, respectively. The third group, represented by the genera Amphiplaga, Trichophanes, and Erismatopterus, is related to the AphododiridcB ;* and as I know of no characters as yet by which to distin- guish it, shall for the present consider it under that head. This family lies on the extreme verge of the order towards the Haplomi, to which the genus Erismatopterus almost affords a transition. * This name is variously spelled, and I am not yet suie as to the orthography to be adopted. •^^ 80 THE WASATCH AND BRIBGER FAHN^. ERISMATOPTERUS Cope. Annual Report U. 8. Geol. Snrv. Terra., 1870, p. 427. Dorsal and anal fins short, with two or three strong appressed support- ing spines in front; no other interhaemal spines than those supporting those of the anal fin. Dorsal fin above the anterior median or posterior abdom- inal region. Ventrals originating in front of or opposite to the origin of the dorsal. Pubes sending a limb upwards, which is in contact with the inferior post-clavicle. Teeth minute or (I) wanting. Caudal fin bifurcate. I originally referred a species of this genus to the Cyprinodontida, and many of the characters are similar to those of that family. The arc of the mouth is formed by the premaxillary bone, and the ventral fins have a rather anterior position, which is neither pectoral nor ventral, and the caudal is furcate; the scales are cycloid. The strength of the spinous fin radii and supporting interhfemal spines attracted my attention, and on careful exami- nation I observe other approximations to the type of Asineops and the Aphredodiridce. The inferior post-clavicle is very long and styliform, as in the latter genus, and the pubic bones are slender and directed upwards, so as to rest on the post-clavicles. In one specimen there appears to be an anteriorly directed pubic limb, but this does not exist in other specimens. The pubes do not reach the clavicles, as in true Physoclysti. Vertebrae hour-glass shaped. Ventral radii seven, in the species E. rickseckeri and E. endlichi. Erismatopterus levatus Cope. Annnal Report U.S. Geol. Sorv. Terrs., 1870, p. 428. Cyprinodon lecatui Cope. Proceed. Amer. Philoa. Soc, 1870,p.382. Plate rx, fig. 6-7. Anterior margin of anal fin commencing a little behind, opposite the posterior margin of the dorsal. VertebrjE : 11-14-5, seven between the interneural and interhaemal bones of the dorsal and anal fins. Radii: D. 8, A. II. 8, V. 8. Caudal fin deeply furcate; first anal ray strong. General form elongate, the greatest depth contained three times in the length be- tween the scapular arch and the basis of the caudal fin. Scales preserved, small; seven longitudinal aeries above and seven below the vertebral PERCOMORPHI. 81 column, probably two rows concealed by it. The caudal peduncle is but little contracted. Length from scapular arch to extremity of caudal, ".0335; depth at origin dorsal fin, ".008. Measurements. u. Total length No. 2 055 Length of cranium '. 013 Length to basis D. I 0232 Length tobasisA. I 033 Length to basis V. I 0205 Length to basis caudal - 0466 Depth at D. I 01 Depth of caudal peduncle 0058 There are many individuals on the slabs of Green River slate, some of them perfectly preserved. Many of these slabs represent that portion of the stratum which is highly carbonaceous, portions of it thrown into the fire burning freely. Dr. Hayden, who has brought numerous specimens from this locality, informs me that the laminae exhibit greater numbers of these little fishes. No doubt the carbonaceous character of the shales is due to the decomposition of their bodies. The nature of the deposit, and mode of preservation, remind one strongly of the Cyprinodon meyeri of Agassiz, from the neighborhood of Frankfort-on-the-Main. That species dififers specifically in presenting 18 anal radii. Some of the specimens above described were obtained from the Green River Cut, and preserved for scientific study, by L. E. Ricksecker. Erismatopterus eickseckeri Cope. Annual Report U. S. Geol. Surv. Terrs., 1870, p. 427. Plate VI, fig. 2. Length, three to four inches; head large. Vertebrae: D. 13 ; C. 1(J; r= 29, ten between the intemeural bone supporting the first dorsal ray, and the first interhsemal supporting the first anal ray. There are only seven in this position in E. levatus. Anterior dorsal ray anterior to the point half way between end of muzzle and end of vertebral column. Branchiostegal radii fin distinguishable. Head stout, mouth terminal, orbit equal length of muzzle; maxilliarv bone reaching line of middle of orbit. Scales 6 o 82 THE WASATCH AKD BEIDGER FAUN^. small, with numerous concentric and no radiating giooves. Fin radii: D. 11, —8 (last split); C. 8—19—8; A. II— 9. V. 7, p. 15. Measurements. M. Total length No. 1 0743 Cranium to supraclavicle 018 Length to base D. 1 029 Length to end vertebral colonin 06 Length of A. II 008 Length of cranium No. 2 .0175 Length to prcopcrculum 012 Length to D. I 0275 Length to A. 1 043 Five more or less complete specimens of this fish were obtained by Lucius E. Ricksecker from the Green River shales, and I dedicate it to him in recognition of his interesting discoveries in this department. Its difference from E. levatus is seen in the more anterior position of the dorsal fin, more numerous vertebrae, etc. Ebismatopteeus ENDLicni Cope. Bulletin U. S. Geol. Snrv. Terrs., 1877, p. 812. Plato Xn, fig. 5. The radial formula in this fish is: D. Ill— 11 ; C. 6-19-6; A. Ill— 7. V. 7. The vertebrae are: D. 13; C. 17; Centra between the lines of the first interneural and first interhaemal spines, 10. Ten rows of small scales visible above the vertebral column. The general form of the fish is stout, and the caudal peduncle is deep. The top of the head is convex, and the eye large. The front descends abruptly to the rather projecting muzzle in the specimen, but whether this is a distortion or not is uncertain. The coracoid is wide and well produced backwai-d, while the clavicle is, as usual, directed forward. The femur is slender, and connected with its fellow by a posterior transverse bar. The greatest depth is a little less than one-fourth the length without tlie caudal fin. The diameter of the eye is one-fourth the length of the head. The origin of the ventral fin is in advance of the first dorsal ray; the origin of PEECOMOEPHI. 83 the anal is below the penultimate dorsal ray. The caudal fin is openly forked. Measurements, M. Total length 061 Length of head 016 Length to line of ventral fin 020 Length to line of dorsal fin 022 Length to line of anal fin 031 Length to base of caudal fin 048 Depth at caudal peduncle 008 Depth at dorsal spine Oil The more numerous rays of the dorsal fin, and more numerous scales are among the characters which distinguish this species from the two above described. It is dedicated to Dr. Frederick M. Endlich, geologist in charge of one of the parties of the United States Geological Survey of the Territories under Dr. F. V. Hayden. AMPHIPLAGA Cope. Bulletin U. 8. Geol. Surv. of the Terrs., 1877, p. 812 (August 15). Generally as in ErismaUypterus, but with strongly ctenoid scales. The dorsal fin is over the abdomen, and is supported by a few strong, adherent spines in front, which rest on stout interneurals; the soft rays have no inter- neurals, either in this fin or the anal. They are present in Erismotopterus. The ventrals originate a little in advance of the line of the dorsal, and the caudal fin is deeply forked. This genus approximates Aphrodedirus. The scales in this genus are thin and like those of Trichophanes. In other respects Amphiplaga resembles that type, and I have only distinguished it on account of the absence of interneural bones below the soft dorsal radii. It has occurred to me that this may be abnormal or due to accident, but the bases of the dorsal radii, as well as the anterior interneural bones, are perfectly preserved, so that the accidental removal of the posterior interneurals seems improbable. It must also be remembered that the inter- hsemal bones are absent from the soft anal rays in both this genus and in Erismatopterus. But one species of this genus is yet known. 84 THE WASATCH AND BRIDGER FAUN^. Amphiplaga bkachyptera Cope. Bulletin U. S. Geol. Surv. Terrs., 1877, y,. 812. Radii: D. II — 8; A. Ill — 4. Vertebrae of the caudal series 15. Scales: transverse row, 22; longitudinal row behind first interneiiral bone, 40. The only specimen I possess lacks the head, so that various characters cannot be ascertained. The depth of the body at the first dorsal spine enters the length from that point to the base of the caudal fin two and a half times, giving a general form of medium proportions. Caudal peduncle stout. The vertebrce are contracted medially, and not shortened; they have two or three longitudinal keels, which are somewhat irregular in their connec- tions. This species is larger than any of the Erismatopteri yet known. Measurements. ^ u. Length from first dorsal spine 073 Length from first anal spine 051 Length of aual fin 023 Length of second dorsal spine .' 015 Length of third anal spine 013 Depth at first anal spine 018 From the Green River shales at Twin Creek, Wyoming. ASINEOPS Cope. Proceed. Amer. Philos. Soc., 1870, p. 380. Annnal Report U. S. Geol. Snrv. Terrs. , 1870, p. 425. Branchiostegal radii, seven; ventral radii I. 6-7. Opercular and other cranial bones unarmed; scales cycloid. Spinous and cartilaginous dorsal fins continuous; caudal rounded; anal with two spines. Lateral line distinct. Operculum with regularly convex posterior border. Teeth coarsely villiform, without canines. Both spinous and soft portions of dorsal and anal fins moderately scaly. This well marked genus is established on the remains of numerous individuals, in various states of preservation, so that the characters undis- tinguishablo in one can be discovered in another. Thus the lateral lino is preserved in one only, and the teeth in another. In none can I be entirely sure that I see the vomer. The scales are preserved in many specimens, and I cannot find a ctenoid margin in any, nor any radiating sculpture, but delicate concentric PEKCOMOEPHI. 85 ridges continued round the central point proximally, distally forming para- bolic curves, the less median not completed, but interrupted by the margin of the scale. Near the margin all the ridges become gently zigzagged. There is no depression between the two portions of the dorsal fin, though the cartilaginous portion is the more elevated. Laid backwards, the latter is in line with the extremity of the anal, and both extend beyond the basis of the caudal. The affinities of this genus are rather obscure, but are in some degree to that aberrant family of Physoclysti, the Aphredodirida. This is indi- cated by the increased number of ventral radii, the slender separated pubes, and the reduced number of interneural spines. The Aphredodiridce betray Physostomous tendency in the same characters, with still greater reduction of the spinous dorsal and anal fins, though its ctenoid scales and spinous orbital and preopercular bones are of Physoclyst significance. In Asineops the scales are cycloid, and the cranial bones unarmed. The ventral fins occupy nearly the same position as in the extinct genus Erisniatopterus Cope, which accompanies it. There is at least in these genera another illustration of the approximation of forms now very distinct, in past periods. The pubes are, however, supported by the clavicles in Asineops, and by the ^wst-clavicles in Erismatopterus, though the latter bones are very long in Asineops also. Asineops will thus constitute a family Asineopidce difieriug from the Aphre- dodiridas in the simple pubes. I suspect that the genus Pygceus of Agassiz will be found also to belong to it, though the increased number of ventral radii is not assigned to it in the Poissons Fossiles. Some of its species may even be found to belong to Asineops. Nine species are described by Pro- fessor Agassiz, all from Monte Bolca, in Italy, from an Eocene stratum. Asineops squamifrons Cope. Proceed. Amer. Philos. Soc, 1870, p. :381. Annual Eeport U. S. Geol. Surv. Terrs.,, 1870, p. 426. Asineops viridensis Cope. Annual Eeport 1870, p. 426. Plate rX, fig. .5; PI. x. General form suboblong, the greatest depth just behind the head, and contained two and a half times in the length exclusive of caudal fin. Radii D. VIII— IX, 14; A. II, 11-12; C.14;V.I, 7; P.?ll?13. Scales5— 86 THE WASATCH AND BRIDGER FAUNiE. t30 — 10, vertical line counted a little behind the ventral fins. The line of the extremities of the second dorsal and anal fins, marks the basal third of the caudal fin. The dorsal spines are subcylindric, slightly curved, and of nearly equal length; the length equals the depth of the body at the middle of the second dorsal fin. The external series of villiform teeth are stout of their kind, conic, and a little incurved. I cannot see the pharyngeal bones or teeth. The number of vertebrae which extends between the caudal fin and the superior margin of the operculum, where one or more are concealed, is twenty- five, of which fifteen are of the caudal portion (in two I can only count fourteen). The mouth is directed obliquely upwards and is rather large; the man- dible, when closed, does not project beyond the premaxillary border. The maxillary, where preserved, is naiTOw distally, and does not project beyond the posterior line of the orbit. The latter is rather small, and though not well defined in any specimen, is not more than one-eighth the length of the head, and 1.5 to 1.75 times inside of muzzle. The margins of all the oper- cular bones are entire and smooth. The interoperculum is narrow, and lies obliquely upwards, narrowing the operculum. The greatest width of the latter is more than two-thirds its depth. The pelvic supports of the ventral fins are simple, slender and in contact anteriorly, their length about half that of the fin. The pectorals are not elongate. The scales extend over the top of the head, to or beyond the orbits. They also extend along the ramus of the under jaw. Those of the fins are quite small, they extend to a considerable distance on the unpaired and on the caudal fins. Measurements. M. Total Iciigtii of tho largest specimen 19 Do. No. 2, smaller example (with caudal) l~ Length of hcail of do 014 Depth of 7 Length to first anal spine 0r>7 Length to base of caudal 086 Dei)th at orbit 0:iO Depth at first dorsal spine Ol:J Depth at first dorsal soft ray 035 Depth of cauilal peduncle 014 Two specimens of this fish have been received from Twin Creek. Tliey are somewhat injured, and it is possible that better specimens will show minute serrations of the preopercle. Priscacara testudinaria Cope. Plate I, fig. 7. My best specimen of this fish is without the greater part of the skull; othenvise it is nearly complete. Under the circumstances it is difficult to make a final generic reference, but as the parts jireserved are identical witli those included in the definition of the genus Priscacara, I refer it here for the present. The specimen is larger than those which I have seen of the other PEECOMOEPHL 99 species of the genus, agreeing in this respect with another which I have seen in the museum at Salt Lake City. It is also more elongate in its form, and is further characterized by its large scales. The more general charac- ters are, the undivided dorsal tin ; the wide interneural spines, and the well developed basilar interneurals. Also the haemal spines of the caudal fin retain the division into three or four parts. The vertebrae have a flat medi- an, lateral rib, bounded by a fossa above and below. The lower border of the inferior fossa on the dorsal vertebrae is deflected. The anterior base of the neural spine is excavated on the second, third, and fourth vertebrae, behind the scapular arch. The lateral rib of the second is oblique vertical. On the fifth and sixth it has an excavated, down-looking superior border. The scales, which are beautifully preserved, though much disarranged, are about as deep as long, with the anterior border subtruncate. The borders, excepting the posterior, are marked with four lines of growth, and from fivo to ten grooves radiate from the center, across the posterior border lines. There are numerous minute elevated points on the center of the scale, and the same reappearing on the posterior border, give the ctenoid character. Radii: D. XI — 12; A. -f 21 -{-. The number of the rays of the infe- rior fins cannot be ascertained, but there may be counted between the first and last, the impression of eleven interhaemal spines. The dorsal spines are very stout, and the first is very short. The ventral spine is not very long, but is very robust. The interhaemals that support the anal spines are extraordinarily robust. The outline of the body is an elongate oval, the depth at the ventral fin entering the length without the caudal fin (or head) two and two-fifths times. Vertebrae: D. from scapular arch, 8; C. 16. Measurements. M. Length ■svithout head and caudal fin 255 Depth at posterior base and fin 044 Length of series of caudal vertebrie 140 Depth from vertebra to ninth dorsal spine : 026 Vertical diameter last dorsal vertebra OH Length of fifth dorsal spine 052 From the calcareous shales of the Lower Eocene, near Manti, Utah. A small specimen, apparently of the young of this species, was sent me by Dr. A. S. Packard. It is of a more elongate form than any of the other 100 THE WASATCH AND BRIDGER FAUN^. species assigned to this genus, the depth at the first dorsal (the length of the head) entering the total four times. The muzzle is short and the eye large, apparently in consequence of the immaturity of the fish. Radii : Br. 5; D. X — 8; A III — 12. Vertebrae from edge of operculum, D. IX, C. XIV, or from two to four more than in any other Priscacara. The three spinous anals are robust as in other species of the genus, while the first ventral spine is long and strong and deeply ground on the inner side. The numbers of soft rays above given is subject to revision owing to the condi- tion of the specimen. Total length, M , .058. From the shales of City Creek Canon, near Salt Lake City, Utah. This specimen indicates a great northern extension of the Manti shales. BATRACHIA. Remains of Batrachia are rare in North American formations later than the Permian. There are two or three species of Stegocephali known from the Trias, above which formation that order is not known to extend in any coun- try. No Batrachians have been obtained from the Jurassic or Cretaceous systems excepting from the top of the latter, in the Laramie. Here occur the genera Scapherpeton and Hemitrypus Cope. A single specimen from the Eocene is mentioned below, and then wo miss them until the Loup Fork or Upper Miocene, where Anura and salamanders have been found. The vertebral column and part of the cranium of a probably incom- pletely developed tailless Batrachian, were procured by Dr. F. V. Hayden, from the fish shales of the Green River ep6ch, from near Green River City, Wyoming. They are not sufficiently characteristic to enable me to deter- mine the relation of the species to know forms. It is the oldest of the order Anura yet discovered, the fossil remains of the known extinct species having been derived from the Miocene and later formations of Europe. REPTILIA. 101 REPTILIA. The Eocene period, was, of the divisions of the Tertiary, the most prolific of reptilian life. It is true that the orders of reptiles which charac- terized the Mesozoic periods no longer existed. The Dinosauria had perished from the land; the Ichthyopterygia, Sauropterygia and Pythononiorpha no longer inhabited the sea, and the Pterosauria had disappeared from the air. The Eocene reptiles were not a new creation, nor a new evolution, but a remnant of the types that had coexisted with those monarchs of life during previous ages. We must except from this statement the serpents, which first appear at this time.* The crocodiles, tortoises, and lacertilians represent orders already abundant in the Mesozoic faunae. Their decadence in central North America did not commence until the Miocene period, when the crocodiles and nearly all the tortoises disappeared. From the Loup Fork or Upper Miocene, only a few traces of lizards have been obtained, and snakes were apparently not very numerous. On the eastern coast regions crocodiles existed, and tortoises were more numerous during the Miocene period; but here also they were less abundant and varied than during the Eocene. The Crocodilia did not differ in important respects from those now existing. I have distinguished five species from the Wasatch beds, and six different ones from the Bridger. The Tesiudinata include a great variety of forms. I have seen sixteen species from the Wasatch formation, and thirty-two from the Bridger and Washakie. Of these, six are common to the two formations, as indicated by imperfect material, leaving a total of forty-two. Three genera, Emys, Trionyx, and f Plastomenus hold over from the Cretaceous period, while six appear for the first time. Of these, five genera are not known to continue later than the Eocene period. Of lizards I have obtained the remains of a half dozen of species, but none of them in a complete state of preservation. Professor Marsh has been more fortunate, as he has described from his material from the Bridger beds, twenty-one speciesf He arranges these under five generic heads, as fol- • Since the above was written, it is reported that Dr. Sauvage, of Paris, has discovered the remains of a serpent in the cretaceous formation. i American Journal of Science and Arts, 1871, June, and October, 1872. 102 THE WASATCH AND BRIDGER FATIiTiE. lows: Thinosaunis Mai>h, five species; Glifptosattrus Marsh, eight species; Xest02)S Cope (1873, Oreosaunis Marsh, not Peters), five species; Tinosaurus Marsli, two species; and Iguanavus Marsh, one species. As Profesor Marsh does not give us any clue to the aflinities of these forms, they cannot be furtlier considered here. In Lieutenant Wheeler's Survey Report* I have pointed out that the dermal scuta and a few other fragments Avhich I obtained in the Wasatch beds of New Mexico, were probably referable to the Flacosaurida, a family created by Gervais to receive certain Lacerdlia of the Eocene of France. To this family no doubt some of the species described by Marsh from the Bridgor horizon are to be referred. The snakes of the Eocene are not very numerous as to species. The first known j^merican species {Palcrojihis Uttoralis and P. halidanus) were determined by myself from Kew Jersey specimens. None have been pro- cured from beds lower than the Bridger, and in that formation I found a single foi-m. Professor Marsh has described five species.* The whole number of species of reptiles thus far discovered in the Eocene of the central region of North America is as follows: Crocodilia 12 Tcstudiiiat.i 42 Lacertilia 22 Opbiilia 6 82 OPHIDIA. PROTAGRAS Cope. Paleontological Bulletin No. 3, p. 3, August 7, 1872. Aunual Report U. S. Gcol. Surv. Terrs., 1672 (1873) p. 632. Proceed. Amer. Philos. Soc., l!?72, p. 471. Transverse processes large, the extremity entirely occupied by the costal articular surfiice. This consists of a superior and an inferior convex por- tions, which are separated by a constriction, which is most profound on the posterior border. Zygosphene wider than articular cups, and giving rise to a low ridge which extends along the side of the neurapophysis. Articular ball and cuj) wider than deep, the former looking very obliqely upwards, its surface extending to the bases of the neurapophyses. A prominent ridge connects the pre- and postzygajjophyses. A strong hypapophysial keel, and a latero- inferior ridge extending posteriorly from the base of tlie transverse process. • Vol. iv, pt. ii, p. 42, pi. xxxii, figs. 26-36. OPHIDIA. 103 The only extinct genus with which it is necessary to compare the present one, is the Boavus* of Marsh, which was described more than a year previously. There are various points in which Professor Marsh's full description con-esponds with my specimens, but I observe two important dif- ferences: One is, that in Boavus the diapophyses are said to be "convex throughout," while here they present a median constriction, giving a figure eight outline. The other is, that the cup and ball are "more nearly verti- cal" than in Boa; the ball is very oblique in Protagras. The modern affinities of Protagras will be fully considered in connection with the Ophidia of the Miocene period in a later portion of the present work. But one species is known as yet. It was found in the Bridger beds of Wyoming. Protagras lacustris Cope. Paleontological Bulletin No. 3, 1872, p. 3. Proceed. Amer. Philos. Soc. loc. sup. cit. Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 632. Plate XXUI, figs. 17-18. A serpent of about the size of the existing pine snake {Pityophis me- lanoleucus). A vertebra before me has the longitudinal hypopophysial keel horizon- tal, and terminating in a very obtuse point. The ball looks extensively upwards. The upjDer articular extremity of the diapophysis is short and obtuse, and the inferior equally so, and directed shortly downwards, their articular surface being continuous with each other. It sends an obtuse latero-inferior keel backward, which terminates distinctly in front of the ball. Its inferior angle stands below the inferior margin of the articular cup. The angle connecting the diapophysis and zygapophysis is strong, while the former is narrow. Measurements. M. Length of centrum with ball, below 0090 Elevation behind, total 0135 Elevation before, total - 0119 Width between di.ipophyses, below 0055 Width of articular cup 0054 Depth of articular cup 0043 Depth of inferior keel 0010 Found by myself in the Bridger bad lands of Cottonwood Creek, Wyoming. * American Journal Science and Arts, 1871, May. 104 THE WASATCH AND BRIDGEB FAUNiB. 1LACERTILIA. CHORISTODERA. Cope, Proceedings Academy Phila. 1376, p. 350. Vertebral centra amphiplatyan. Processus dentatus free from axis. Neural arches separate from centrum during maturity. CHAMPSOSAURUS Cope. Loo. oit. p. 348, pnblisbed Jan. 30, 1677. Paleoatological Balletin Xo. 23, p. 9, Jan. 10, 1877, Simado- taurua Gervais, Journal de Zoologie, 1877, No. 1, p. 76, f February. This genus was established on species found in the Laramie Cretaceous formation. It has been found to be abundant in the Puerco of the Tertiary series, and is hence introduced here. The characters presented by the vertebral column are the following: The ribs have a single head, which articulates with a prominent tuberculum, excepting those of the cervical vertebrae. On these there is a small capit- ular tubercle below the diapophysis. It commences very small, and inferior in position, being removed, in fact, but a short distance from the inferior middle line in the first vertebra in which it appears. It rises rapidly in the succeeding centra until it is merged in the tuberculum of the diapophysis. The latter projects from the neural arch, which is free from the centrum, but in none does the base of the diapophysis rise from a point above the floor of the neural canal. On the dorsals it is vertically compressed. One of the anterior cervicals, probably the axis, is obliquely truncated below its anterior articulate face, for a free hypopophysis or os odontoideum. This vetebra has no parapophysis, and the articular faces for the neurapophysis are superior. The few vertebrae in each of several series, probably from the sacral region, are more depressed than the others, and the facets for the diapophyses present a greater antero-posterior extent, but none are coossi- fied. The caudal vertebrae are distally quite compressed. In all, except the anterior ones, the neural arch is coossified with the centrum, and in such there are no diapophyses. In those with free neural arch, the facets for the neuropophyses turn down on the sides of the centrum. The articular extremities of the centra are plane, those of the caudal series slightly concave. There are no hypapophyses behind the axis, ex- CHORISTODERA. 105 cepting a longitudinal carina, which ceases to exist on the dorsal vertebrae. The zygapophyses are simple. The chevron bones are free. The relations of the atlas and axis, though not fully elucidated by my specimens, are peculiar. The former has separate neurapophyses, which have nearly the shape of those of the Streptostylicate Reptilia, resembling much those of the Pythonomorpha. Although I procured numerous cervical vertebrae, there are but few which exhibit the antero-inferior facet for sup- posed hypapophysis, already described. The position of this vertebra was in front of the first cervical which displays a parapophysis, and is, on this account, likely to be the axis or the third cervical vertebra. It is the more probably the axis, as there is no other among the large number of verte- brae in my collection which can be referred to that position. Its anterior articular face is smooth and like the posterior, showing that the odontoid bone was not coossified with it. Now in the Crocodilia the odontoid bone is united with the anterior extremity of the axis by suture, which may be- come coossified with age, while the free hypapophysis is w^anting. In the streptostylicate orders the hypapophysis is present, and the odontoid is above it, but united to the axis by suture. On the other hand, in the Rhyncho- cephalia, the axis is coossified with both odontoid and hypapophysis, and a few succeeding vertebrae possess fre^ hypapophyses. A few entire ribs and the heads of many others have been obtained. The cervical ribs are long, and the dorsals are relatively stout and shoi-t The head of an anterior dorsal is truncate and compressed, its articular face contracted, forming a narrow figure eight. The shaft is obliquely flattened. The extremities are separated from the lateral surfaces by a narrow angle, as though capped with cartilage in life, as in the Pythonomorpha. Bones of the extremities are very rare. One fragment resembles the proximal end of a crocodilian tibia, and another is like the distal half or more of the tibia of the same type. The above characters were derived from the Laramie species, and those of the Puerco agree with them exactly in those respects. The latter enable me to add, that the jaws are slender, and that the splenial bone of the man- dible is well produced anteriorly. The teeth are set in shallow alveoli, and are replaced from the inner side as in Lacertilia and Pythonomorpha. 106 THE WASATCH AND BEIDGER FAUN^. Dr. Lemoine has toimd this genus in the Suessonian formation near Reims, France, and liis material has enabled him to furnish some characters in addition to the above mentioned. He states* that the quadrate bone is "non sonde," find that the limbs resemble both those of Crocodilia and Lacertilia, and are apparently adapted to aquatic habits. Ignorance of the structure of the skull has prevented a definite conclu- sion as to the true position of this genus and its allies. Dr. Leraoine's ob- servation makes it appear that they belong to the Streptostylicate division, and that they form an aberrant division of the LacerfiUa or Pythonomorpha. For the present I refer them to the former, but they will constitute a dis- tinct sub-order with the definition given on a preceding page. Besides Champsosnurus, the Champsosaurklce include the genus Ischyrosaurus Cope, which difiers from it in the heavy subfusiform ribs, and the flat articulation between the centrum and neural arch of the vertebrae. This genus was named by Professor Gervais at nearly the same time with myself His publication was made in the February no. of the Jour- nal de Zoologie for 1877, and mine in the Proceedings of the Philadelphia Academy for December, 1876. My description did not appear until Jan- uary 10, 1877, and although I do not know of the precise date of the pub- lication of the Journal de Zoologie, it was presumably not until some weeks later. There have been four species of this genus described from the Ameri- can Laramie formation, viz: the C. profundus, C. annectens, C.brevicollis, and C. vaccinsulensis. The species from Reims is called C. lemoinei Gerv. I distinguish three species from the Puerco bed of New Mexico, which dift'er from the Laramie species in obvious ways. Vertebrae of a species from the Laramie were figured without name by Leidy in the Transactions of the American Philosoph. Society, 18G0. The Puerco species differ as follows: Small; dorsal centra witli semicircular faces, much wider than' deep; an- terior dorsal keeled below C. amtralis. Large; dorsals witii cordate faces aliti^le wider than deep; none known to be keeled below C. puereeitsit. Medium; length, width, and depth of dorsal centra equal; faces snb- - round ; not keeled below; axis not keeled below C. saponensis. "Coromnnication siir li-s Ossomcnts foagilcs desTerr. Tortiaires Iiifs. dc8. Euv. do Reims; Assoc. Fran;, jioiir IWvanc't ilcs Soiriices, IH^O, p. 15. CH DKISTODEEA. 1 07 Champsosaueus australis Cope. American Naturalist, 1861, p. 670 (July). Plate XXIIIlj; figs. 1-4. Eleven vertebrse, probably ofone individual, were found by Mr. Baldwin, mingled with jaw fragments, with teeth of the Eocene Mammal Catathlceus rhabdodon. All the pieces are enclosed in the black ferruginous matrix, in which the mammalia of the Puerco epoch are found embedded. The vertebrae, are of about the same size and form, and all belong to the dorsal series. Thej^ are characterized by their large width as compared with their depth, differing in this respect from all of the known species. The centra are regularly rounded below, and the borders are scarcely at all flared. One of the dorsals, probably an anterior one, has a prominent angular keel in the middle line below. The outline of the articular faces for the neural arches is pyriform, the wide portion concave, with its external edge decurved, and on the anterior half of the side of the centrum. The decurvature is sometimes sufficient to resemble part of a rib-facet. Articular faces of centra nearly plane. Sides of centra very little concave, a shallow fossa below the base of each diapophysis. Non-articular surfaces of centrum marked with a delicate thread-like sculjjture. and there is no coarse sculpture near the edges of the articular surfaces. Diameters of keeled dorsal centrum: anteroposterior M. .012; vertical .014; transverse .017. Diameters of a rounded dorsal: anteroposterior .013; vertical .012; transverse .015. The dorsal vertebrte are wider and more transverse than in either of the four known American species. They are longer than those of the C. vaccinsulensis, and lack the marginal wrinkles of the C. saponensis. From near Canyon Largo, San Juan River, New Mexico. Champsosaurus puercensis Cope. Proceeds. American Philosoph. Society, 1881, Dec. p. lO.") (1882). Paleontological Bnlletin No. 34, 1882, p. 195, Feb. 20. Plate XXIII ^3 ; figs. 5-10. This species is represented by a number of fragments, which include three dorsal and four caudal vertebrae of apparently one individual. They represent an animal of larger size than any of those heretofoi'e referred to Champsosaurus, excepting the C. vaccinsulensis. In all of the vertebrse the neural arch is more or less coossified with the centrum, and the animal had probably reached its full size. 108 THE WASATCH AND BUIDGER FAUN^. One of the dorsal centra is split vertically and longitudinally, and shows the structure already figured by Leidy in the Ischyrosaurus antiquus* Leidy. The surface exposed displays two diagonal lines of fissure crossing each other at right angles. They indicate clearly the mode of origin of this amphiplatyan type of centrum. The centrum is first deeply amphicoelous, as in the Theromorphous reptiles of the Permian. The conical cavities are filled by the ossification of the remaining portion of the notochord, forming a conical body which always remains • distinct from the remainder of the centrum. The articular faces of the dorsal centra are a little wider than deep, and the depth about equals the length of the body. They are not nearly so depressed as those of C. australis, and their outline is diff"erent. This is wider above and narrows below; in both C. australis and C. sajionensis the inferior outline is part of a circle. None of the dorsals preserved are keeled below. There is a fossa below the diapophysis which has a subvertical pos- terior boundary. The general surface (somewhat worn) does not display wrinkles near the articular faces. An anterior dorsal has a short compressed diapophysis with a narrow figure 8 articular surface, and its superior border in line with the roof of the neural canal. The anterior caudals have sub- round articular faces; the posterior are more oval, and the bodies com- pressed. With greater compression the length increases. Measurements. u. I anteroposterior 0-i5 Diameters of an anterior dorsal s vertical (hJ5 ( transverse 030 Heiffht of costal facet of do .'. 021 _. . , lit vertical 007 Diameters neural canal do. ( I transverse 009 / anieropoeterior 0"24 Uianieters anterior caudal < vertical 021 ( transverse 021 Santeropoaterior 025 vortical 018 transverse 018 The typical specimen was found by Mr. Baldwin near the Puerco River west of the Nacimiento Mountain, New Mexico, in the typical locality of the Puerco formation. •Trans. Auicr. Philog. Soo. 1860. CHOEISTODERA. 109 Champsosaurus saponensis Cope. Paleontological Bulletin No. 34, p. 196 ; Feb. 20, 1882. Proceedings Amer. Philos. Society, Dec. 1881, p. 196, 1882. Plate XXIII b ; figs. 11-22. Represented in my collection by six cervical and several dorsal verte- brae; one only of the latter with well preserved centrum, parts of ribs, and various other bones, whose reference is not yet certain. The cervical vertebrae include the os dentatum or centrum of the atlas. This shows its streptotylicate character in its distinctness from both the cen- trum and the free hypapophysis of the axis. Nevertheless, it is more Croc- odilian than Lacertilian in form. Its anterior face is transverse, with a little lip carrying forwards the floor of the neural canal, below which the face is bevelled posteriorly. The inferior surface is narrow and transverse, as though adapted for the anterior part of the hypapophysis of the axis. At each side it terminates in a prominent tuberosity, as though for the attach- ment of a cervical rib as in the Crocodilia. The anterior face is bounded posteriorly by a transverse groove which terminates in a down-looking fossa on each side. The i)osterior articular face of the os dentatum is wider than deep. The lateral angles of the superior face are rounded, and its median portion is concave. The axis displays a large facet for the hypapophysis. Behind it the infe- rior middle line is not keeled, but is coarsely wrinkled longitudinally. The posterior edge of the hypapophysial facet is the most prominent part of the inferior surface. The posterior articular face is deeper than wide. This is true of the faces of all the cervical vertebras. The latter gradually increase in size posteriorly, and the dorsals become larger. The articular faces of all the centra are regularly rounded and not contracted below. The five cervicals are strongly keeled below, the keel of the third centrum being split up anteriorly into narrow ridges On the sixth the keel is more prom- inent and acute. The dorsal is not keeled. A trace of the parapophysis appears low down on the fourth cervical ; it rises and becomes prominent as a rounded tuberosity on the fifth and sixth. It appears on the superior edge of the centrum of the dorsal vertebra, where it is connected with the diapophysis. It is near the middle of the length of the centrum, and not near the anterior border, as in C. australis. 110 TDE WASATCH AND BRIDGER FAUN^. The surfoees of tlie vertebra; are very smooth, excepting where thrown into coarse wrinkles near the border of the articular faces and near the hypapophysis. The edges of the articular faces are somewhat revolute on the sides in the cervicals, but not on the doi"sal. They are impressed in the centre to a point, most strongly so as we pass forward in the series. There is a fossa below the space anterior to the parapophysis of the dorsal verte- bra, which is abruptly bounded below by a horizontal angle. A separate neural spine, perhaps of a cervical vertebra, has the following form. It is stout and contracts rather abruptly at the apex from behind forwards. The section is broadly lenticular, angulate in front and truncate behind. The posterior foce has several longitudinal wrinkles, including a median raised line, and there are some more irregular wrinkles on the sides. Mea,surements of vertebra:, Autcriorface of os deutatum ^ width 025 4 depth (oblique) 012 Posterior face of 03 deutatam I ^^'*ltli 020 \ depth 018 Length 03 dentataiu above 014 (posterior face J *l''I'f'' ^^- Diamoters axis ^ < width 020 ( length 0185 Hypopopbvsial facet OS dentatuuJ ''''I'"' ^^ l width 014 ^. , . . , ( leUL'th 022 Diameters fourth cervical < , ■, ^^ n.v.= < anterior •^"Ptli ^^^ \ width 022 . , (length 0215 Diameters sixth cervical < ^ i .i i>.>i.- < anterior M«l"l^ ^^'' < wid vidth 02;i5 Space between parapophysis and diapophysis of do 0040 ^. _ _ , , , ( length t'2l)5 (pth O2G0 id(h 02C5 anierior . jd< ( w Height of neural spine of f from postliypapophysis "210 Anteroposterior width of do. at base 0100 The portions of ribs are separated heads and shafts. The former are doul)le and therefore cervical, and are quite large. If the shafts belong to them, tlie neck of this species must have been wide. The shafts are slender and of dense bone. The section is oval at the middle, but towards the dis- tal extremity becomes flattened and grooved, and delicately lined on one side. The extremities of the long bones are without condyles, but have concave surfaces like those of the ribs. The bodies are robust and angular. They may be abdominal ribs of unusual stoutness. From the Puerco beds. 1). Haldwin. rp TESTUDIXATA. Ill TESTUDIXATA. As the Eocene forms of this order are of unusual interest, I give an analysis of the extinct genera of the Cryptodire division, which have been found in North America and Europe up to the present time. In the check-list of the North American Batrachia and BeptUia,^ I enumerated nine families of this division of the Testudinata, three of which are extinct. Subsequently another extinct family, the Baenidse, was added. I now define all of these families. I. Plastrou uot articulated to tlie carapace, but presenting to it more or less open digitations. Dactylosterna. Phalanges of anterior limb without condyles, and covered by a common integument ; eight pairs of costal bones Cheloniida'. Phalanges of anterior limb without condyles ; nine or mtfre costal bones . Propleuridce. ' Phalanges of anterior limb with condyles ; digits inclosed in tlistinct integ- uments ; eight costal bones ; sternal elements united by digita- tions and inclosing fontanelles ; caudal vertebrae procoelous . Trionychidce. Phalanges of anterior limbs with condyles ; digits distinct ; eight costal bones ; .•sternal elements united by suture and mclosiug no fontanelles ; caudal vertebrae opisthocoelous Chelydridw. II. Plastrou uniting with the costal bones of the carapace by suture, with ascending axillary and inguuial buttresses. (Feet, ambulatory.) Clidosterna. A Intersternal bones present. No intergular scuta Pleurosternidce.\ Intergular scuta ; caudal vertebrae optisthocoelous . Baenidce. A A 'So intersternal bones. a Intergular scuta. A mesosternal bone . . Adocidce. a a Xo intergular scuta. A mesosternal bone ; three series of phalanges Emydidce. No mesosternal bone ; three series of phalanges Cinosternidce, A mesosternal bone ; two series of phalanges Testtidinidw. III. Plastron uniting with the marginal bones of the carapace by straight suture only. (Feet, ambulatory.) Lysosterna. No intersternal bone nor intergular scutum; a mesosternal bone and three series of phalanges Cistudinidce. The extinct species of the Cryptodira of this continent belong to eight of the above families. I give diagnoses of the genera to which they are referred. Names of existing genera are in Roman type. * Bulletin U. S. NatioDal Museum, No. 1, 1875. p. 16. t There are two genera of this family, neither of them yet found in America ; Pleurosiernum Ow. •vrith smooth shell, and Helochchjs Meyer, with 8culi)turod shell. 112 THE WASATCH AND BKLDGER FAUN.E. Cheloniid^. Postabdominal bone« distinct from each other. Chelouia Brong. Postabdominal bones united with each other l\v suture.. Puppigeru* Cope, Propleukid^ Cope.* Transactions of American Philo8oi>bical Society, xir, 1870, p. 235. Ten costal bones; tirst two marginals united with carapace by suture ; shell smooth, flattened Osteopygis Cope. Nine costal bones; flrst two marginals united to carapace by suture; shell sculptured ; a high dorsal keel Feritresitts Cope. Nine costal bones; one marginal united with carapace by suture; second by costal gomphosis; shell not keeled nor sculptured. Propleura Cope, t Nine costal bones; first united with carapace by suture; second without costal gomphosis ; shell not sculi)tured Catapleura Cope. t Nine costal bones ; marginals all free ; shell not sculptured Lytoloma Cope. TRiONTcnm^. a Surface of l>ones smooth. Postabdominal suture digitate Axestus Cope. a a Surface of bones sculptured. ,9 Sutures of plastron digitate. A dermal flap ])n)tecting posterior legs below ; marginal bones. . . . Emyda Gray. A dermal flap ; no marginal bones Cyclanosteus Peters. No dermal flap nor marginal bones; muzzle much abbreviated Chitm Gray. No dermal flap nor marginal bones; muzzle elongate Trionyx Geoflfr. y9 /9 Suture for post-abdominal coarsely serrate. Postabdominal recurved in front Plastomenus Cope. ClTKLYDRIDiE. a Bridges of plastron wide ; f caudal vertebrai. One row of marginal scuta; six pairs of scuta of the plastron Idiochelys Myr. One row of marginal scuta; scuta of i)la**tron ?not distinct IIydropelta\ Myr. a u Bridges of plastron very narrow. ft Carai)ace smooth, not sculptured. Two rows of marginal scuta ; five pairs of scuta of the plastron . . Macrochelys Gray. Oue row of marginals ; five pairs on plastron Chelydra Schw. One row of marginals ; four pairs of scuta on plastron . Claudius Cope. ;9 ji Carapace sculptured. One row of marginal bones Anostira Leidy. Baenid^. Cope, Annual Report U. S. Gool. Surv. Terrs., 1872 (1873) p. 621. Supramarginal scuta (lUitimeyer)and intormarginal scuta; no inter- humerals Platychelys Myr. No iiiterliuineral scnita; no sui)ramarginals Jiaena Leidy. luterhuiiieral S(;uta; no supramarginals .... . Polythorax\ Cope. 'J'ala-orhrlyf norimcuntiiliiH GeolTr. liclongs to tlii» family, Vint not Valaoihclys Mjr. \ EanfHtrmum WnKii. {I'aliromeduiia ct Acicluhif Myr. liili' Klilinieyer) is nearly allied to BydropfUa, t Povsi Illy one uf lliv AJocitUe ; see Proceed. Aca.aE. udinidae. Hydraspididse. Chelydridce. \ EmydidcB. Baenidte. Cheloniid^. Pbopleukid^. ADOCrD.^E. Sphargididce. Pbotostegid^. Trionychidte. / 116 THE WASATCH AND BKIDGEK FAUNiB. AXESTUS Cope. i»roceed. Amer. Pbilos. Soc, 1872 p. idi, (publiNLed July 29). Annual Report U. S. Gool. Surv. Terrs., 18/2 (lb7:!), p. 615. This is a genus of Trionychidae which is represented by a species not fully known. The type specimen is represented by bones of the limbs and various vertebrae, with the post-abdominal bone of the left side. The general characters are those of Trionyx. The scapula is elongate, the procoracoid long and narrow, and the coracoid of medium width. The humerus is sigmoid, with widely separated tuberosities, and flattened extrem- ity, with marginal groove. The femur is also curved, but less strongly than the humerus, and has a median anterior low angular ridge. The claws are large, some curved, and some entirely straight. The cervical vertebrae are relatively large and elongate. The two sacrals are free from the carapace above, have broad articular surfaces for diapophyses, and flattened centra. The caudals are procoelian, and have short diapophyses. The post-abdomi- nal bone has the form seen in existing Trionyx. It presents two dentate processes forwards for the hyposternal, and two inwards to its mate in front. It is prolonged backwards and inwards into a flat process. It is especially distinguished by its tenuity, and the entire absence of the superficial sculp- ture of Trionyx. The usual dense layer is present, but is quite thin, and exhibits the peculiar decussating pattern of lines of deposition character- istic of the same layer of the dermal scuta of Crocodilin. No portions were obtained which can with certainty be referred to the carapace. The ilium is short, stout, and recurved, and the pubis is largely expanded. AxESTUs BYssiNus Cope. Loc. cit. Plate XV, figs. 1-12. The procoracoid and scapula are of equal lengths, and the coracoid is much dilated distally. The portions of plastron preserved are thin for the size of the animal, and all the bones are especially dense and smooth. The post-abdominal has the free margins acute and serrulate. There is an external, gently convex edge, with a long process extending backwards; and one long narrow one inwards. The dense layer is marked with decussating lines of osseous TESTUDINATA. 117 deposits, as in woven linen The cervical vertebra is without spine; it is not depressed in the middle, and is without any pneumatic foramen. M. Length of cervical vertebra 0C8 Diameter at middle OiO Diameter at end 035 Diameter of caudal vertebra at ball 010 Length of caudal vertebra 023 Length of an ungual phalange 043 Proximal depth of an ungual phalange 013 Length of post-abdominal, broken 180 Width of post-abdominal 120 A hyposternal bone of a large Trionychoid turtle displays the charac- ters of this genus in its absence of superficial sculpture, and in the decus- sating bone structure of its borders and processes. It belongs to a species of the size of the A. byssinus, but is so much more massive than the post-ab- dominal bone of that species that I suspect that it belongs to a distinct one. Its median surface presents a few faint traces of tubercular roughening. Occasionally^ the supei-ficial layer of the bones of the plastron of species of Trionyx of this formation, are found nearly smooth, but they do not display the decussating bone structure, nor the thin edges of the species of Axestus It has often occurred to me that these peculiarities may be the result of erosion, and that the animals possessing them should be referred to the genus Trionyx. This may be the case, but there are two objections to such a view. First, the middle, or more prominent parts of the bone, where the attrition must be greatest, displays the characters least; second, if we imagine that movements of the limbs have caused the attrition, we are met by the fact that the decussating structures appear on the inner borders of the bones where the limbs do not reach. The typical specimen was found on Black's Fork of Green River; the second specimen on Upper Green River. TRIONYX Geoifr. Turtles of this genus were very abundant during the Eocene period in North America. They disappeai'ed from the interior basin with the close of this period and did not reappear ; but they continued on the Atlantic slope, and are to-day abundant in the tributaries of the Mississippi and in the streams that flow into the Gulf of Mexico. 118 THE WASATCn AND BKIDGER FAUN.E. Tliero were evidently several species of Trionyx during both the Wasatch and Bridger epochs ; but the specimens found are generally so fragmentary, that it is difficult to ascertain what characters can be relied on to distinguish them. In the Paleontology of New Mexico (Wheeler's Report) I enumerated five as occurring in the Wasatch formation of that region, but I am not sure that more than three of tliem will ultimately be found to deserve that distinction. In vay collection from the Bridger beds I have three manifestly distinct species, and I am compelled to admit two others. Of the five, I regard two as identical with New Mexican Wasatch species, and one as common to the Bridger and Wasatch beds of Wyoming. The proper definition of the doubtful species must be left to future discovery of better material. The Eocene Trionyches may be distinguished in tabular form as follows : I. Sculpture of the extremities of the costal bones thrown into ridpes. a Superficial layer of costal boues overhanging rib extremities. Eidges clo.se together T. lepiomitus. Eidges widely separated T. cariosits, a a Superficial layer of costal bones, sloping into free rib ends. Eidges widely separated T. raduln.i. Ridges do.se together, interrupted and vermiform .... T. ventricosux. II. Sulpture of the extremities of the costal boues honeycombed or punctate. Carapace with .seuljjture all honey-combed ; six vertebral bones ... T. vintaensis. Carapace covered with pits which are little wider than their inter- spaces ; seven vertebral bones T guttatm. Carapace with longitudinal ribs crossing the ends of the costals; pits small T. concent ricus. Carapace with longitudinal ribs along its middle ; seven vertebral bones ; pits not large T. heteroglyptua. III. Sculpture of extremities of costal bones, consisting of small tubercles formed of the broken ridges. Carapa<'<' honeycombed with large fossaj ; no ribs ; seven verte- bral bones T. sciitumantiquum. Tlie Wasatch species are : T. hptomitus, T. cariosits, T. radidus, T. ventricosus, T. guttatus, and T. scutxiinantiquum. The Bridger species are : T. radulus, T. uintaensis, T. guttatus, T. conccntricus, T. heteroglyptus, and T. scutuniantiquum. TESTUDINATA. 119 Trionyx radulus Cope. Systematic Catalogue of the Vertebrata of the Eocene of New Mexico; U. S. Geo. Geol. Expl. W. of 100th Mer., G. M. Wheeler, 1875, p. 3.5. Report Paleontology, do. iv. ii, p. 45. Plate xxvi, figs. 11-16. This turtle is nearly allied to the T. cariosus. As in it, the proximal portions of the costal bones and the vertebral bones are honeycombed, while the distal parts of the former are parallel-ribbed. Five to nine of these ribs can be counted from the free end. They are not closely placed, being narrower than their intervals. The size of the species is the same as that of T. cariosus, but the costal bones are more uniformly thinner. A specimen from the Bridger beds shows a rather wide, smooth band, along the front of the carapace. Measurements. K. Thickness at front of carapace at middle 010 Thickness of a costal bone at middle of border 006 Three ridges at end of costal in 010 I have but one specimen of this species, in many fragments, from the Bridger formation. Trionyx guttatus Leidy. Trimyx guttatus Leidy, Report U. S. Geol. Surv. Terrs. (4to), p. 176, pi. ix, fig. 1. Cope, Report Expl. Surv. W. of 100th Mer., G. M. Wheeler, iv. pt. ii,p. 46. T. uinlaensis Leidy, Cope, Syst. Catal. Vert. Eocene New Mexico, p. 35 (not of Leidy). This is the most abundant species of the Bridger formation, and I obtained parts of many individuals. Its characters are expressed in the definition already given. To it must be added that the distal ends of the costal bones are beveled regularly to the free rib-extremity. Almost the entire carapace of one of the individuals of this species was obtained by myself in New Mexico. The pitting is uniform and without interruption, extending even to the sutural edges of costal bones. It is strong on the vertebral bones, but, near the distal ends of the costals, becomes obscure ; the border itself being smooth. The ribs separating the pits are coarse, but not so wide as the pits. The posterior part of the carapace of a Bridger specimen has the last two pairs of costals in contact, showing that there were only six vertebral bones. The pits are rather small, having, in some places, interspaces as wide as themselves ; this is, however, not generally the case. The dividing 120 THE WASATCU AND liKlDGEU FAUN^. ridges are always wider and more obtuse than in T. scutumantiquum and T. uintaensia. I did not obtain the last-named species in Wyoming, so far as I know, and I refer to Dr. Leidy's work for a full description of it and of the T. guttatus. Trionyx heteroglyptus Cope. Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), p. C16. Plate XVI, fig. 2. Carapace broad, flat, concavely truncate behind. Free portion of costal bones short. The last pair of costal bones are in contact by a common suture by about two-thirds their width, the anterior portion being separated by the last vertebral bone. There is a great diflference between the sculpture of the middle of the carapace and its lateral portions. The former region is coarsely ribbed longitudinally, the intervening grooves being mostly unin- terrupted. On the middle portions of the costals the ridges are more or less broken up, and distally they are very delicate, forming an inosculating pattern, inclosing small pits. On the last costal they retain their ridge-like character. The posterior vertebrals are marked by a single groove down their middle. Mea«uremenU. M. Width of (■■ara])ace at antepenultimate cost.al bone 235 Length from front of carapace at autepenultimato costal bone backwards 095 Width of car-ajHice at antepenult iniate costal distally 048 Length of last two vertebrals 037 This is a handsome species, and appears to be rare, as I have but two specimens that I can definitely refer to it. It is, however, difficult to dis- tinguish separated ends of costal bones from those of T. guttatus. I dug one of the specimens from the summit of the Church Butte, Wyoming. Trionyx concentricus Cope. Proceed. Amer. Philos. Soc, 1872, p. 469 (published July 29). Plate XVI, figs. 3-6. This species reposes on various fragments, in one case representing numerous poitions of a carapace. The sculpture is intermediate between those of T. hderoglyptm and T. guttatus. The costals have subequal and subruund pits throughout the entire length of the bones, but their inter- 8 o TESTUDIXATA. 121 spaces are raised into longitudinal ribs at intervals of from one to three rows of pits. These ribs are equally developed at both ends of the costals. Measurements. M. Width of a costal bone uear middle 020 Thickness of costal bone near middle 003 The type specimen is smaller than that of the last. From Cottonwood Creek, Wyoming. Trionyx scutumantiquum Cope. Annual Report U. S. Geo. Geol. Surv. Terrs. 1872 (1873), p. 617. Plate XVI, fig. 1. Established on a nearly perfect carapace and part of the plastron from the bad lands of Cottonwood Creek. These indicate the largest species of the genus yet found in North America. The carapace is a longitudinal oval, broadly rounded in front. The median line forms a marked depression, and the costal bones rise and descend again, forming an arch on each side. The free portion of the ribs is not very long The sculpture consists of numerous honeycomb-like pits separated by rather narrow ridges. On the middle parts of the carapace these are subequal, but on the middle of the length of the costals all the ridges run together longitudinally, and on their distal parts, these are broken up so as to produce innumerable irregular tubercles and pits. The lines of the intercostal sutures are smooth. Eight costal bones, and an anterior mar- ginal coossified with the first costal by its entire width, and sending out a broad costal extremity, which curves backwards, its anterior margin smooth. Eight vertebrals, the last separating the anterior portions of the last costals. Measurements. M. Length of carapace 425 Greatest width ot carapace, axial 410 Thickness of fifth costal 0075 Thickness of fourth vertebra 034 Thickness of centrum of vertebra 010 Several fragmentary individuals from the Wasatch beds, near Black Butte, Wyoming, as also one from the corresponding formation on Bear 122 THE WASATCn AND BlilDGEU FAUN^. River, resemble this species more nearly than any other. They display similarity in the fineness and acuteness of the ridges between the fossc-B, and their disposition to break into small tubercles on the distal parts of the costal bones. More perfect specimens will be neccessary to decide whether this species is common to the two horizons or not. PLASTOMENUS Cope. U. S. Geol. Surv. Terrs. 1872, p. G17. Ri-port Expl. Surv. W. 100th Mer., G. M. Whcolcr, iv, pt. li, p. 47, 1877. The structure of the skeleton in this genus remains incompletely known in spite of the abundance of specimens which I have procured in the Eocene beds of the West. As already stated, it is allied to the genus Trionyx, but differs in some important points in the bones of the plastron. The hyosternal bones which I have seen in P. multifoveattts are generally like those of Trio- )ii/x, while the hyposternals, if I have con-ectly identified them, differ mate- rially. These elements are preserved in the species named, and in P. cor- rugatus, and here they display a transverse width behind the inguinal region more like an Emydoid than a Trionychoid genus. The inguinal border is thickened, and at the bridge somewhat recurved. The inguinal buttress is in all three of the species more robust and more vertically directed than in Trionyx. The post-abdominal suture is closer and less digitate in the P. tri- onychoides. In P. corrugatus there is a fontanelle at the supposed post-ab- dominal suture, as in Trionyx, while there is no indication, of one in the P. trionychoides. The hyposternals also display a more completed ossification than in Trionyx, in the fullness of the borders between the internal and external digitations. Thus, in P. multifoveatus, the internal border is regu- larly convex, and the processes for the episternal bone scarcely project beyond it. The external digital process projects more extensively, while the free ends of the ribs extend little or not at all beyond the border of the caraj)ace. Among the various remains from AV'yoming and New Mexico, no marginal bones have been found, nor dermal scutal sutures. Portions of the skeletons of the species of this genus are very abund- ant in the Eocene of New Mexico and Wyoming. Though one seldom obtains an entire carapace or plastron, the form, size, and sculpture indicate TESTUDINATA. 123 that the remains belong to several species. The figures, composed of ridges, pits, etc., variously distributed, are often quite elegant. The species do not attain the average size of the Trionyches of the same era; but the P. com- munis, P. lachrymalis, and P. muUifoveatus exceed in dimensions the living species of that genus of North American waters. The three species above named, in which the sternal characters are evident, are the only ones which can certainly be referred to the genus ; but several others from the Eocene beds can with much probability be referred here also, the whole number being eight. Four species from the Fort Union Cretaceous beds have been referred to Plastomenus, but, as already remarked, as a provisional arrangement until their structure is bet- ter known. The P. thomasii is also of uncertain reference to this genus. J. Surface without welts, or with the sculpture thrown into ridges : a. No ridge-lines : Surface with sharp, fine wrinkles P. corrttgatns. Sui'face with more remote wrinkles, little inosculating P. trionychoides. Surface honeycombed with thick, inosculating ridges P. muUifoveatus. a a. Sculpture thrown into ridge-lines : Surface coarsely honeycombed with fine ridges P.fractus. II. Sculpture interrupted with solid welts; pits small or reduced to puuctfe: Surface with transverse ribs separated by one or two rows of pits P. scriaUs. Welts on all the thin costals, and separated by numerous pits P. molopinus. Welts only on the posterior costals, which are all thick; numerous punctfe between them P. comnumis. Welts broken up into short ridges behind ; intervening surface punctate. P. lachrymalis. Welts represented posteriorly by tubercles separated by smooth surface, anteriorly unbroken ; the surface punctate P. ademius. Of these species, P. corrugatus, P. muUifoveatus, P. fractus, P. seriaUs, P. communis, and P. lachrymalis have been found in the Wasatch beds of New Mexico ; and the P. trionychoides, P. muUifoveatus, P. molopinus, and P. cedemius in the Bridger beds of Wyoming. Plastomenus trionychoides Cope. Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 619. Anostira trionychoides Cope, Proceed. Amcr. Philos. Soc., 1872, p. 461 (published July 29). Plate XVI, fig. 1. The original specimen of this species was found mingled with one of Anostira ornata, and being of about the same size, the two were supposed to pertain to a single species. -I subsequently distinguished the fi-aginents 124 THE WASATCH AND JJKIDGKR FAUNJE. ■clearly, and find portions of another individual from another locality to pertain to the same. The sculpture of the costal bones consists of reticulated ridges which inclose coarser pits than in the next species, and show no tendency to run into ribs extending obliquely acrossthe bones. The first costal exhibits a greatly beveled suture for the nuchal, and its alar portion behind its costal rib is twice as wide as the latter. The last costal differs from that of P. thomasii in being angulate instead of truncate at the rib-extremity, and the latter projects strongly beyond the angle. The sculpture of the costal bones is somewhat like that of Trionyx scu- tumantiquum. It can hardly be regarded as the young of that species, for, although of small size, the complete ossification of the costal bones indicates that the specimens are of mature age. Bad lands of Cottonwood Creek, near Fort Bridger, Wyoming. Pj.astomenus multifoveatus Cope. Anim.al Keport U. S. Geol.'Surv. Terra., lt<72(187.'?), p. G19. Report U. S. Geo. Geol. Siirv. W. of 100th Jlcr., iv, pt. ii, p. 49. P. thomasi p.irs. Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), p. C18. Plate XVII, figs. 2-8. Represented by various parts of four individuals, a sufficient number of identical pieces being present in all to insure their specific unity. The bones of both carapace and plastron have a honeycomb pattern of reticu- lation, with shallow pits, which on weathering become punctaj. The intervening ribs tend to connect into ridges running diagonally across the costal bones. The pits tend to form linear series parallel to the bordei-s, on some of the bones of the plastron. The latter are gently convex at the transverse suture. The last costal is very wide, and is in contact with its fellow on the median line as in other species of the genus, except .a sutural margination behind, apparently for a pygal bone. The outer border is straight, truncating the last rib-extremity. Meaatircmcnts. M. Thickness of a costal 004 Wiillli luHt eostal, iliHtally 04(J Wiiltli of liyostemal 018 TliiikiH'HH of liyosternal 005 Lengt li of a vertebral 018 Width of a vertebral 014 TESTUDINATA. 125 Both the hyosternal and hyposternal bones are more convex than in any of the Triomjclies of the Eocene period. The ing'uinal edge is thinned, and is very gently concave. The hyosternal is much thicker on the outer part of its posterior suture than at the internal part Of course the same is true of the hyposternal. The latter is characterized by the steepness of the ascent of its external buttress, which is also situated neai-er to the hyosternal suture than in Trionyches generally. The external sculptured layer rises on its base and forms a narrow rim below the inguinal edge of the posterior part of the hyposternal for a short distance only. The pits of the inferior surface of the hyosternal are more or less parallel with the borders of that bone, while those of the hyposternal are irregular. In a costal bone of a large specimen, the sculpture is a shallow, but sharply impressed honeycomb pitting, smaller than in the preceding species Thus there are seventeen or eighteen pits across the middle, to seven or eight in P. trionychoides. No ribs whatever Measurements. M. Width of costal at middle 240 Width of costal at end 350 Thickness at middle 0035 I included the specimens of this species in my descriptions of P. tho- masiin the Annual Report of the United States Geological Survey for 1872. When I stated there that P. tJiomasi is the type of the genus Plastomenus, I referred to these specimens; it is therefore to be observed that the type of this genus is really the P. multifoveatiis The true P. thomasi was founded on. sternal bone perhaps of a small species of Trionyx. Some of the specimens of this species were found on Cottonwood Creek, Wyoming, and others on the Upper Green River. Plastomenus molopinus Cope. Annual Keport U. S. Ceol. Surv. Terrs., Hayden, 1872, p. 602. Anostira molopina Cope. Proceed. Amer. Philos. Soc, 1872, p. 461. Plaatomemis communis Cope, var. ii, Cope. Report Expl. Surv. W. of 100th Mer., Lieut. G. M. Wheeler, iv, pt,,ii, p. 50. Plate XVII, figs. 9-14. This tortoise was common in the Bridger epoch in Wyoming, and also in the Wasatch in New Mexico. My collection from the beds of the former includes eight individuals in a fragmentary condition. I have already men- 126 THE WASATCn AND BRIDGEIl FAUN^. tioned those from the latter horizon as a thin variety of P. communis, and figured some costal bones on Plate xxv, figs 5-G, of the Report of Lieutenant Wheeler, above quoted. It is probable that Dr. Leidy has figured part of a costal bone on Plate xvi, fig. 12, of the final Report of Dr. Hay den, vol. i. The costal bones of this species are generally ribbed towards the distal ends ; some of them at the proximal also. The ribs are not close together as in P. serialis, and their directions are somewhat irregularly transverse to the length of the costal bone. The sculpture of the surface between them is punctate rather than reticulate, since the impressed fossae are not wider tlian the intervals between them. The difference between this species and the P. communis is found in the much thinner bones of the carapace. A portion of the last costal bone of one of the specimens is without impressed jDunctae. Its ribs are thickened, and run parallel to the median line. Were they broken up into tubercles I would refer the specimen to P. cedemius. I do not possess the corresponding part in any other specimen. The size of the P. molopinus is about that of the P. cedemiits, and is less than that of my examples of P. muUifoveatus. Measurements. M. Width of a costal bone, proximally 018 Thickness of a costal hone, proximally 004 Width of another costal bone, distal ly 020 Width of the same costal bone, distally 003 The specimens are from various portions of the Bridger basin. Plastomenus cedemius Cope. Annu.-U Keport U. S. Geol. Surv. Terrs., 1872 ;1873), p. 619. Jnoitira ademia Cope. Proceed. Amor. Philos. Soc, 1872, p. 461 (July 29). Plate XVII, figs. 15-17. Represented by parts of three specimens. These all display the last and middle costals, and two of them the second costals. Sternal bones are wanting (except, perhaps, in one). From these it appears that the anterior costals have a distantly punctate sculpture, with rib-like swellings running diagonally across them. On the middle costals the punctae disappear and the ribs grow thicker ; on the last costals the ribs are broken into a number of smooth tuberculai* swellings whose axes are nearly at right angles to that of the carapace. The second TESTUDINATA. 127 costal has its posterior alar portion twice as wide as the rib portion ; its suture with the first costal is very oblique, and is bounded behind by a rab- bet-edge. The last costals are peculiar in their union throughout their entire length without emargination for pygal, and in the gently convex posterior outline (with projecting rib end), differing in these respects markedly from P. multifoveatus and P. trionycJwides. Measurements. No. 1. Length of last costal common suture 045 Length of last costal anterior suture 063 Length of last costal exterior horder 052 Width of middle costal 021 Thickness of middle costal 004 No. 2. Width of first costal, proximally 026 Width of first costal behind rib, distally 014 No. 3. Width of middle costal 021 This handsomely marked turtle is quite peculiar in its sculpture, which departs more from ordinary patterns than any of those referred to the present genus. Two specimens from Cottonwood Creek, Wyoming. ANOSTIRA Leidy. Proceedings of Academy of Natural Sciences, 1871, p. 102. In this genus the epidennis was thin and adherent to the bones, and not divided into scuta. The carapace is composed, as in Emydidce, of costal vertebral, and marginal bones, the last united to the first by suture and gomphosis. The series of vertebrals does not continue to the caudal except by the intervention of a pygal. The sternum is cruciform, with narrow longitudinal prolongations or lobes, and narrow bridges. It appears not to have possessed any fontanelles, but the presence of mesosternum is not yet fully made out. The cranium and limbs are unknown. This genus must be regarded as an interesting intermediate type con- necting Plastomenus and Chelydra or Dermatemys. In skin and sculpture it is identical with the first; in carapace and plastron most like Chelydra. Two species, a large and a small, are known. ilOM^ 128 THE WASATCH AND BRIDGEE FAUNiE. Anostira kaduuna Cope. Proceediogs Amcricau Fbiloeophical Society, 1872, p. 555 (published October 12). Plato XVII, figs. 18-19. Based on two marginal bones, one from the front the other from the rear of the carapace of an animal of twice the bulk of the largest Anostire previously found. Apart from size, the sculpture is peculiar. It consists in the anterior marginal costal bone, of closely packed vermicular ridges which run out flat on the posterior and upper edge. In the posterior, it consists of only closely placed minute tubercles over the whole surface, which are more or less confluent on the proximal part of the bone. Measurements. M. Length of front marginal on free edge 025 Width of front marginal on free edge OiS Length of posterior marginal on free edge 025 Width of posterior marginal on free edge 025 The specimen on which this species reposes cannot well be regarded as an overgrown A. ornata, since the sculpture of the bones is not enlarged in proportion to the size of the elements of the skeleton. The tubercles and ridges are not larger than those on a small A. ornata. One specimen from the Bridger bad lands of Hams Fork, Wyoming. Anostira ornata Leidy. Proceed. Acad. Phila., 1871, p. 102. Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 174. Plate ivi, figs. 1-6. This species has been so fully described by Leidy, that I only give a brief synopsis of its characters. The outline is a broad oval with an open emargination in front. The median dorsal line is keeled posteriorly, as far as the posterior border. The posterior marginal bones are thickened so as to have in part a triangular section. The margin is acute and not or but little recurved. The sculpture of the costal bones is in obsolete ridges running parallel with the middle line, and close together. That of the marginals is in small tubercles which run together at the proximal part of the bone above, and generally on the inferior surface. The branches of the plastron are all narrow, and the transverse ones TESTUDIISrATA. 129 quite long-. The external borders of the latter are coarsely dentate, but not digitate. The sculpture of the plastron is obsolete. The size of the Chelopus guttatus or Chysemys pidus of our streams. Specimens were found by myself and party on Cottonwood Creek, and on the Upper Green River, Wyoming. EMYS Brong. The species of the Eocene formation which have been referred to this genus are evidently members of the family Emydidce ; but owing to the absence of descriptions and specimens of the crania, it is not certain to which genus of the family they should be referred. As in similar eases in paleontology, they are retained in the genus Emys until reasons for distin- guishing them shall be discovered. As already remai-ked by Leidy, the species so referred, have left more numerous remains in the Bridger beds than those of any other genus. The same is true of the Green River and Wasatch formations, the genus Trionyx only having left more abundant traces in the latter. During my explora- tions in Wyoming, in 1872, I detected three species in the Wasatch and Green River beds, one in the Washakie, and four in the Bridger formation; in 1874 I obtained two species in the Wasatch strata. These species may be briefly distinguished in tabular form, as follows : I. The bridge sutures on not, or moderately, elevated axillary and in- guinal buttresses. a Dorsal line with projecting keel. Vertebral bones smaller, thicker U. polycypha. Vertebral bones larger, thinner; gular plates not reaching meso- sternal bone ; grooves moderate U. terrentris. Vertebral bones larger, thinner ; grooves very deep and wide .B. megaulax. a a No dorsal keel. i? Gular scuta not extending on mesosternum. • Bones massive, with lines of growth on some; costals swollen at proximal end of costal scuta U. testudinea. Bones thinner ; no lines of growth ; costal bones flat E. euthneta. yS ,3 Gular scuta extending on mesosternal bone. y Vertebral bones wide. Shell thin ; lip of plastron not very wide H. lativertebralis. ■f y Vertebral bones elongate. Shell thin, little arched ; vertebral scuta wide ; sutures of plastron straight ; its lip narrower B. vyomingensU 9 130 THE WASATCH AM) liKlDCiKK FAUN^. Shell rorv thick, little nnhed ; vertebral scuta wide; sutures of plas- trou straight ; its lip nurrow E. shaughnaigiana. Shell thiu, little arched; vertebral scuta wide; lip of plastron very wide . E. latilahiata. Shell thin coossified, much arched above ; sutures of plastron irreg- ular ; vertebral scuta longer than in other species E. haydeni. II. Axillary and inguinal buttresses very i)roinineut. Shell thin, carapace convex, not keeled ; scutal sutures not deep E. septaria. The distribution of these species is as follows : Wasatch, Wyoming — £. tastudinea, E. evthneta, E. megaulax; New- Mexico — E. lativertehralis. Bridger, Wyoming — E. pohjcypha, E. terrestris, E. tvyomingensis, E. shaughnessiana, E. latilahiata, E. haydeni. Washakie — E. septaria. It is true that in many Emydidce the young stages are characterized by a dorsal carina and greater width of the dermal scutal grooves. Dr. Leidy has suggested * that the immature stages of Emys wyomingensis are repre- sented by certain keeled specimens in his possession ; and also states that the mesosternal bone is more elongate in such specimens than in the larger ones. I have suspected that the forms I have named, Emys pohjcypha and E. terrestris, might be the young of E. shaughnessiana and E. wyomingensis respectively, but I have not identified them on account of the lack of spec- imens displaying intermediate characters, and also because of the shorter gular scuta of E. terrestris. If the mesosternal bone is longer in the young than in the adult E. wyomingensis, it should bear more rather than less of the gular scuta. The Emys megaulax of the Wasatch beds presents the characters of immaturity in the low median keel and the deep and wide sutural grooves. It is much larger than either of the two species just named, and its bones are stout. It cannot be the young of its cotemporary E. euthneta, for that does not exceed it in size. I have parts of several individuals of both for comparison. It is true that in all three of the spe- cies presenting these characters of immaturity, the shells are, so far as known, without fontanelles, and that in the smallest, E. polycypha, the ver- tebral 1 nines are relatively the thickest. • Report U. S. Geol. Surv., i, p. 148. TESTUDINATA. 131 I have not included the E. cihoUensis (Cope Report Expl. Surv. W. of 100th Mer., Wheeler, iv, pt., ii, p. 57), as it may have been founded on a larger E. euthneta. Emys polycypha Cope. Annual Rejiort U. S. Geol. Surv. Terrs., Hayden, 1872, pp. 625, 630. Palaotheca polycypha Cope, Pjocecd. Amer. Philos. Soc, 1872, p. 463. Plate XVII, figs. 20-22. This species of tortoise is indicated by vertebral costal and marginal bones of very small individuals. These bones are, however, not only thoroughly ossified, but are very stout, indicating the adult age of the ani- mal. The deeply impressed scutal sutures, and heavy proportions, as well as the elevated carina of the carapace, indicate affinity with Cistudo or, perhaps Testudo. As a generic character, it may be noted that the vertebral bones are subquadrate, and support the neural canal without intervening lamina. The carina of the carapace is abruptly interrupted at intervals ; some- times with, sometimes without, a pair of pits, one on each side. The marginal bones are well secured and the scutal sutures are deeply impressed on them. Memurements. M. Length of vertebral bone 009 Width of vertebral bone 0085 Length of margiual bone 01 This is the last of the tortoises of the Bridger formation. Emys terrestkis Cope. Annual Report U. S. Geol. Surv. Terrs., Hayden, 1872, p. 629. PaUeotheca terrettrie, Cope, Proo. Amer. Philos. Soc, 1872, p. 464. Plate XVII, figs. 23-25. In this species and the following, the lip only is inclosed by the gular scuta, which only reach the apex of the mesosternal. In neither are the articulations of the bridge with the costals known. Represented by three individuals, one of which may be regarded as the type. They are all thinner than the P. polycypha, and larger, being about equal to the Aromo- chelys odoratus of our ponds. In the type specimen the carina of the vertebral bones is interrupted by a deep sutural groove, which is less pit-like than in P. polycypha. The bone itself is broader than long, being perhaps, from the hinder part of the 132 THE WASATCH AND BIMDGKK FAUX.E, carapace. The (.•hivicular (episternal) bone is preserved. It is character- ized by the considerable and abrupt projection of that part inclosed by the gular scutum, which resembles what is sometimes seen in Testudo. The edge of this i)art is entire and acute. The posterior part of the projection forms a step-like prominence behind, on the superior or inner face. The bone is almost as wide as long, and the niesosternal causes a very slight median truncation, but overlaps much on the inner side. The gular dermal suture does not reach it. Measurements. L«?ngih of vprtebrul bono 00t> Wiatli of vcrtoliral bone 018 Length of epistcmal 02 Wid'.h of cpisteraal (transverse to axis of body) 017 Width of a costal Oil Thickness proximally W^ In the second specimen, a strong groove is seen to bound the lip of the front lobe of the plastron. In it the marginal is seen to be stout, a little recurved, and sharp-edged. A vertebral differs from those of other species in being longer than wide. In a third individual the gular lip is not so prom- inent as in the type, and the mesosternal bone truncates the clavicular exten- sively, giving it thus a more elongate form. The gular scuta expand to its front margin. The marginal bone is stout and sharp-edged, and is not so deeply impressed by the dermal suture as in P. jwli/ci/pha. Emys megaulax Cope. Annual Report U. S. Geol. Surv. Terrs , 1872, p.628. E. pachylomus Cope, loc. cit., 629. Plate XVII, figs. 2G-33. Represented by remains of five or six specimens. They pertained to a species of about the size of the salt-marsh terrapin Malacockmmys palus- tris. The marked ptculiarity consists in the broad and abruptly sunken sutures which separate the dermal scuta of the carapace. This is visible on vertebral, costal, and marginal bones, where the area? between the sutures are abruptly separated. The sutures partially interrupt the dorsal carinn. This is wide and low. The surface is otherwise smooth. The scutal sutures are not so much impressed on the plastron, and those of the gular scutes extend on the mesosternal bone. TESTUDINATA. 133 Measurements. M. Length of a marginal 016 Width of a marginal 023 Width of a vertebral 018 Length of a vertebral 017 The vertebrals are subquadrate in fonn. Neither carapace or plastron are thick. The mesosternal is transversely diamond-shaped, and angular in front. Measurements of mesosternal. Length 023 Width 034 Other fragmentary specimens similar in size to the last, have the scutal sutures strongly marked, but not so widely and deeply impressed. Though they are finer, they interrupt the dorsal carina, which swells up from it, and they divide the flat proximal portion from the much swollen marginal part of the marginal bones. The mesosternal bone is similar in form to that of the last specimens; the only specimen is obtusely rounded in front, and bears part of the gular scuta. From the Wasatch or Green River beds at Black Buttes. A third but uncharacteristic series of fragments from the first Eocene lignite bed above the Cretaceous, probably belong to this species. Emys euthneta Cope. Annual Report U. S. Geol. Surv. Terrs., 1872, p. 628. Plate XVII, figs. 34-42. Represented by numerous portions of several specimens. These per- tained to a species of about the size of the salt-water terrapin, Malacoclemmys palustris. There is no dorsal keel, and the scutal sutures, though distinct, are not very much impressed nor the interspaces swollen. The lip of the plastron is narrow, thick, and not notched; the sutures of the gular scales do not extend on to the mesosternum. The margins of the lobes of the plastron are a little thickened and the sutures of the bones coarse and at the hypoxiphisternal junction, etc., with gomphosis. (It is fine and close at this point in E. testudinea.) The costal sutures for the bridge are projecting and curved, in one position; in the other, straighter, and very near the margin of the costal bone. Surfaces smooth. 134 THE WASATCH AND RKIDGER FAUN^. Abundant in the red beds wliich lie between tlinse identified as belong- ing to the Green River and Bridger epochs at Black Buttes, Wyoming. Emys testudinea Cope. AoDaal Report U. S. Geol. Snry. Terrs., Hayden, 1672, p. 627, Xotomorpha testudinea Cope. Proceed. Amer. Philos. See, 1872, p. 475. Plate XXIII, figs. 12-13. Represented by portions of four or more individuals. In one of these the anterior lobe of the plastron is in part preserved. The mesosternum is a transverse oval, the posterior margin regularly convex, the anterior with three equal borders. The median of these is concave. The sutui-es are radiating, and the groove separating the humeral scuta, appears to traverse the entire length of the bone. The outer surfoce is gently convex. The free margin of the episternal and hyposternal bones is acute, and with an internal thickening, as in Cisindo, Testudo, dr., forming a ridge with abrupt inner face. This face extends backwards as a groove, to the axillary process of the hyosternal, forming a characteristic mark. Although the extremity of the episternal bone is lost, and the mesosternal exhibits no trace of tiie intergular scute, the outer sutures of the gular scuta are so far posterior as to render it highly probable that the intergular plate existed. At the point where this suture reaches the margin, the latter is openly emarginate. The posterior suture of the humeral suture crosses the margin half way between the axilla and the episternal suture, and is not marked by a notch. The last-named suture is transverse. On the xiphisternal bones the groove of the anterior suture of the anals is plainly visible. It is regularly convex forwards, and in one specimen is double. In a second specimen of about the same size, parts of two costal bones are preserved They are thick, and display the usual costal and vertebral scute-sutures, the latter in a groove; for the middle of the vertebrals is ele- vated, and the costals project shoulder-like just outside the groove. In a third specimen a little larger, xiphisternals with several marginals are preserved. A free po.sterior marginal is regularly recurved, and the scute-sutures are deeply impressed. The margiiuil scuta have evidently been marked with concentric grooves within their margins. The first mar- ginal bone of the bridge has a very obtuse edge. In nono of the specimens are the surfaces sculptured. TESTUDINATA. 135 Measurements. No. 1. M. Width of plastron at axilla 086 Length of plastron from axilla (approximate) 05 Thickness of hyostemal at mesosternal 099 Thickness of hyostemal at hypostemal 0005 Width of mesosternal 037 Length of mesosternal ^ t 026 Thickness of a vertebral 006 Thickness of xiphisternal (normal) 004 Thickness of xiphisternal at pubis 007 No. 2. Thickness of costal at hump 0075 Width of costal 0175 No. 3. Width of posterior marginal 027 Length of posterior marginal 019 The mesosternal, though found with No. 1, does not fit it exactly and does not belong to it. From Green River formation near Evanston, Wyoming. Ejtts vyomingensis Leidy. Annual Report U. S. Geol. Surv. Terrs., Hayden, 1871, p. 367, Montana. Proc. Acad. Phila., 1869, p. 66. E. stevensonianus Leidy, loc. cit,, 1870, p. 5, fide Leidy. E. jeanesi Leidy, loc. cit., 1870, p. 123, fide Leidy. Plate XXIII, figs. 9-11. Of this, the most abundant tortoise of the Bridger Eocene, I obtained numerous specimens on my expedition of 1872. I refer especially to three as most characteristic, one a chelonite entire, but with plastron crushed in; a second broken up, but including portions of most of the shell; and, tliirdly, a nearly perfect plastron. These all show that the species had no intergular scute, as finally decided by Leidy. They also show that the notch on each side of the lip of the plastron is not uniformly present. As Dr. Leidy has given a very full account of this species, with good figures,* I do not redescribe it here, but refer to it in the descriptions of the allied species. Emys shaughnessiana sp. nov. Plate XXIII, figs. 3-6. I describe under this name a species, which is represented by the greater part of one individual in a dislocated condition. The separated elements are in excellent preservation, so that the characters can be readily ascertained. 'Report U. S. Geol. Surv. Terrs., i, 1873, p. 140. 136 THE WASATCH AJND BRIDGEB FAUNJE5. The species has the linear dimensions of the E. vyomingensis, and differs primarily in the much greater thickness of the bones of the carapace, especially of the vertebral bones. The plastron is thick, but does not so much exceed the corresponding parts of the thicker examples of E. vyoming- ensis. Another character is the great thickness of the costal parts of the axillary and inguinal buttresses. In an antero-posterior diameter they are twice as large as those of E. vyomingensis, but not more prominent trans- versely. The vertebral dermal scuta are a little longer than wide, and the lateral sutures are strongly bracket-shaped, while the anterior and posterior one present an angle forwards on the median line, thus differing from the sutures in E. haydeni. The vertebral bones are longer than wide anterior to the sixth; the latter, with the seventh, are wider. The costal capitula are quite weak. The posterior marginal bones are not recurved, and the anal is not notched, and its border is a little convex. The lateral and ante- rior marginals are not grooved nor recurved at the margin. The dermal grooves of the carapace are generally strong. The plastron is of elongate proportions as compared with the ordinary E. vyomingensis. The lip is moderately wide, and has a notch on each side, as in the species just named. The mesosternum is wider than long, and is marked anteriorly by the gular scuta. The humero-pectoral groove reaches but does not cross it posteriorly, in which it differs from that of most of the Bridger species. The smooth border of the anterior lobe of the plastron is very wide anteriorly; that of the posterior lobe is even wider at the posi- tion of the ranges of movement of the thigh, where it is bounded within by a sharp groove. The posterior notch is well marked but open. Tlie dermal sutures are straight and not sinuous, as in E. haydeni. Measurements. M. Length of carapace 380 Width of carapace at second costal bone 145 LenRlli of tliird vertebral bone 040 Width of third vertebral bone 025 ThickiicHM of third vcrtebrol bone 016 Length of seveuHi vertebral bono 023 Width of wventh vertebral bono 033 Thi('kllf^!w of w^venth vertebral bone OH Width of axillary buttress 018 Anterior lobe of plastron < . P^, ' " TESTUDINATA. 137 M. 106 axilla 144 Length of bridge 144 Posterior lobe of plastron J . ". . i 'ili^ ,a^ Width of anterior lip 0(58 There is a peculiarity in the form of the lip of the plastron of the specimen on which this species rests, which may be a specific character. Instead of having an abrupt lateral prominence and truncate or concave anterior border, its outline is regularly convex, onl)- interrupted by the notch, which is half way between the median and lateral gular sutures. I dedicate this species to my friend Arthur O'Shaughnessy, of the British* Museum, who has published a number of important papers on her- petological subjects. The specimen above described was found by myself on Cottonwood Creek, near Fort Bridger, Wyoming. Emys haydeni Leidy. Proceedings of the Philadelphia Academy, 1870, p. 123. Annual Report U. S. Geol. Surv. Terrs., 1871, p. see. JS. loyomingenBU Leidy, part Report U. S. Geol. Surv. Terrs., Hayden, i, p. 14, PI. ix, fig. 6. The central parts of the carapace and plastron of an Emys from Cotton- wood Creek, Wyoming, belong to a species distinct from the E. wyomingensis, as it appears to me, and agrees very nearly with the figure and description of the specimen on which Dr. Leidy established his E. liaydeni. In fact, the general appearance of the specimen is that of a Baena, a resemblance produced by the density of the tissue and general coossification of the parts as well as the fineness of the sutures where apparent. The species differs from the E. wyomingensis in the marked and regular convexity of the carapace, both longitudinally and transversely, resembling no little a portion of the shell of an egg. The dermal sutures are straighter and less undulating on the carapace. The vertebral scuta are relatively longer, and their borders are not bracket-shaped laterally, and are very little or not angulate before and behind. On the other hand the grooves of the plastron are irregular, crossing and recrossing the median line at various points. The humero-pectoral suture crosses the mesosternum well in ad- vance of its posterior border. 138 THE VVASATCU ANDBRIDGER FAUN^. The carapace is of moderate thickness, and the capitula are robust, much more so than in the E. shaughnessiana. The anterior marginals are robust; a posterior is much more thickened inferiorly, and is consequently more recurved than in E. sliaughnessiana, and displays narrower marginal scuta. Measurements. H. Lonpth of third vertcliral bono -.045 Widtb of third vert*3brul bono 0;«) I.iMiRlli of third vcrtcbr.il scute 080 Width of third vertebral scute 056 Thickness of third mar(;iiml bone on suture for second 021 Thickness of plastron at middle of hypostcrnal 017 Width of anterior lobe at axilla 140 This specimen resembles the one observed by Dr. Leidy, in having the fourth vertebral bone octagonal, a character I have not met with in any other species. EmYS LATILABIATUS Cope. Proceedings of American Philosophical Society, 1872, p. 471. Represented by a perfect specimen of a tortoise of a broadly oval form, and somewhat terrestrial habit. Its prominent characters are to be seen in the plastron, of which the posterior lobe is deeply bifurcate. The anterior lobe is peculiar in the unusual width of the lip-like projection of the clavic- ular ("episteinal") bone, which is twice as wide as in E. wyomingensis, and not prominent. Bones all smooth ; margins of lobes of plastron thickened. There are three scans, perhaps, of muscular insertions near the posterior margin of the plastron, one oval one opposite to each lobe, and one round one opposite to the notch. As compared with E. septarius this species has no such septa nor sculp- ture ; the emargination of the plastron is more open, and the lip much shorter and wider. ifeasurements. K. Len;;th of earn|iace 255 Width of carapace 2.')0 Width of lip of [ilastron 06 Depth of posterior notch 02 The temporary misplacement of the typical specimen of this species prevents my giving other than my original description. From near Black's Fork of Green River. TESTUDINATA. 139 Emys septaria Cope. Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 625. Plate XVIII, figs. 9-13. Established on a nearly complete specimen of the size of Ptychemys rugosa. The carapace is rather thin and the sutures not obliterated. The vertebrae are sessile on the vertebral bones. The form is quite convex. The plastron is flat and rather stout. The mesosternum is rhombic, the longer angle anterior on the outer side, but posterior on the inner side. Its anterior angle is embraced by the gular scuta. The anterior lobe of the plastron is contracted near the axillae, and flared with a thin edge in front of it, then contracted to the rather narrow lip of the middle front. The posterior lobe is somewhat flared and has a wide beveled margin, and is deeply notched behind, the notch being close, and the lobes projecting. The surface is delicately sculptured with obsolete ridged lines across the axis of the costal bones. The vertebral region is somewhat swollen between the cross-sutures, which present an obtuse angle in the same direc- tion, both before and behind. The scuta are longer than wide, and have bracket-shaped outlines. The surface has the obsolete ridges, which diverge in every direction from the inlooking angle of one end, but are mostly longitudinal. In old specimens this delicate sculpture might become obsolete. Measurements. M. Length (Jf plastron 325 Width of plastron at groin 150 Width of lip 054 Length of lip OL'O Width of clavicular bone behind 041 Width of mesosternal, externally 058 Length of mesosternal, externally 045 Thickness of hyosternal behind 015 Length of vertebral scutum 072 Width of vertebral scutum 068 Width of a costal bone 029 Thickness of a costal bone 006 Found in the bad lands of the Washakie basin, on South Bitter Creek, by the writer. 140 THE WABATOU AM-) BHIDGEII FAUNuE. HADRIANUS Cope. Proceedings of the Aniericau Philosopbical Society, 1872, i>. 468. This genus resembles Testudo in form, but has two anal scuta, as in most Emydiddc. The claws are short and stout ; one ungual phalange is a long oval viewed from above, and is oval in section, with obtuse edges. The articular surface is subinferior. A cervical vertebra is of moderate length and has a very prominent anterior zygapophysis. The centrum presents two distinct convex articular surfaces anteriorly, and one trans- verse one behind. A sacral is free from the carapace above ; it presents two surbround articular cups posteriorly and outwardly ; the anterior are broken off. These characters are observed in a large specimen of H. corsoni. Hadrianus allabiatus Cope. Proceedings of the American Philospbical Society, 1872, p. 471. Plate XIII, iigs. 13-15. This large land tortoise differs from both the //. quadratus and the H. octonarius in the absence of the projecting lip of the anterior lobe of the plastron, which is thus simply truncate. The mesosternum is not cordate, but has much the shape of that of //. quadratus; that is, rhombic. The scutal sutures are dee])ly impressed. The plastron is strongly concave. Carapace without irregularities of the surface. Length eighteen inches. From the bad lands of Cottonwood Creek, Wyoming. Hadrianus octonarius Cope. Proceedings of the American Philosophical Society, 1872, p. 468. Phito XX. The //. octonarius is distinguished from its congeners as follows. It is of elongate form, strongly contracted at the bridges, but expanded and arched above the limbs. The carapace is very convex. The plastron has the posterior lobe emarginate rather tlian bifurcate, as seen in H. corsoni. Each projection represents a right-angled triangle rather than a wedge. The anterior lobe presents an elongate lip, which is expanded and slightly emarginate, at the end. The mesosternal bone is heart-shaped, the posterior emargination being widt; and not very deep. TESTUDI]S^ATA. 141 The anterior margin of the carapace is somewhat flared above the limbs. The nuchal scutum is very narrow transversely, but elongate. The cara- pace descends steeply and is incurved in the middle of the posterior margin. The superior portions of the anal scuta cover an ovate projection of the surface. Measurements. Length (below) 730 Width .at middle 4:17 Width .at hind limbs 525 This species is perhaps the largest of our extinct land tortoises, and is founded on a beautifully perfect male specimen from the bluffs of Cotton- wood Creek. Hadrianus corsoni Leidy. Geological Survey Montana, 1871, p. 365. Tistudo hadriaiius Cope, Proceed. Amer. Philos. Soc, 1872, p. 463. Sadrianiis qitadratits, loc. cit., p. 468. Indicated by several individuals, one nearly perfect, the others rep- resented by all parts of the skeleton. This proves the existence of a very massive species of the terrestrial genus Iladrianus. The plastron presents a short, wide lip in front, which is turned outwards, forming a strong angle with the plane of the upturned front of the lobe. This lobe is bordered by a thickening of the upper surface, which cuts off the basin from the lip, as a high ridge. The posterior lobe is deeply bifurcate, each post-abdomnal projecting as a triangle. There is a notch at the outer angle of the femoral scute. The hyposternal bone is generally thickened within the margin above, and an elevated ridge bounds the basin of the plastron behind, as anteriorly. The middle of the plastron is thin. The carapace is without marked keel or serrations. It is remarkable for its expanded and truncate anterior outline, which is nearly straight between two lateral obtuse angles, thus giving a quadrate outline when viewed from above or below. Length of carapace, "TSO — 20 inches, width ".630. The marginal scuta are nar- row, and there is a large nuchal plate. Abundant in the Bridger beds. 142 THE WASATCH AND BRIDGER FAUN^. DERMATEMYS Gray. Annals Mag. Nat. His., 1847, p. 60. Catal. Shield Reptiles British Musonm, 1855, p. 49. Baptcmy Leidy, Proceed. Acad. Phila., 1670, p. 4. Report U. S. Geol. Surv. Terra., i, 173, p. 157. This genus is similar to Emys in the structure of the carapace and plastron, except that the lobes of the latter are narrowed and shortened. The scuta are similar, excepting that there is a series of intermarginals on the bridge on each side. There are thirteen marginals on each side, those of the last pair in contact throughout. In a specimen of the extinct species of the Bridger, I tind a trace of an intergular scute, as is sometimes seen in D. berarcU now living in Mexico. Dermatemys vyomingensis Leidy. Baplemyi icyomtnjwtsi*, Report of the United Statos Geological Sun-ey of Territories, i, 1873, p. 157. Plates xii, and xv fig. C. This tortoise is not uncommon in the Bridger beds, but generally in a dislocated or fragmentary condition. It is readily distinguished as a species by the elevated keel of the posterior vertebral and pygal bones. The mesosternal is large and emydiform, and is not marked by the humero-pec- toral dermal suture. It is extensively occupied by the large gular scuta, which exceed in size those of any other species of the formation. The size rather exceeds that of the average Emys vyomingensis. The Wasatch species D. costilatus* Cope diflPers in having an obtuse keel on the costal bones, parallel with the median line of the carapace, as in Staurotypus tri- porcatm. NOTOMORPHA Cope. Proceedings of the American Philosophical Society, 1872, p. 474. This genus reposes on a clavicular or episternal bone, which gives characters not seen in any other genus known to me. The sutures are dis- tinct and fine, and the form of the mesosternum is emydoid. The gular scuta are small, and occupy an angular space between the large intergular and humeral, which are extensively in contact. It is uncertain whether there are two or only one intergular. The general characters of the other •H<^port Expl. and Siarv. \\ . 100th Mer., (J. M. Wh(-«ler, iv, pt. ii, p. b1. TESTUDINATA. 143 bones are those of the less aquatic types of the Emydes. It is hkely, as ah-eady remarked, that this genus belongs to the Adocidce. The following were the characters with which I commenced the origi- nal description of the genus: "The elements of the carapace and plastron are massive, and the former was well arched ; both exhibit well-defined grooves for the sutures of the dermal scuta. The mesosternum is broad ovate, and the bones of the plastron are united by immovable sutures. The elevated lateral processes of the hyo and hyposternal bones are not broad and unite by suture with the lower plate of the first and last bridge- marginal bones. They are thus recurved in both cases, but none of the ribs indicate any sutural union as is seen in various genera. The costal bones unite with the marginals by serrate suture. In one species a large intergular scutum has left its impression, the gulars being lateral and rather small. The anterior lobe of the plastron is emarginate." I then added that the pubis was united by suture with the post-ab- dominal (xiphisternal) bone, and inferred that the genus should, therefore, be referred to the Pleurodira. I subsequently became convinced that the bones showing this sutural union are really costals, bearing sutures for the buttresses, and that there is no evidence to show that the sutural union of the pubis and ischium which chai-acterizes the Pleurodira exists in this genus. At the same time, having doubts as to the homologies of the dermal scuta observed, I referred the species which displays the supposed intergular bone to Emys. While I believe this course to be the proper one in the case of one of the species {Emys testudinea) referred to Notomorpha, I now be- lieve that the characters displayed by the other species {N. gravis) justify the retention of the genus Notomorpha. The only species known to me was obtained from the Wasatch forma- tion of Wyoming. NOTOMOEPHA GRAVIS Cope. Proceed. Amer. Philos. Soc, 1872, p. 476. N. garmani loc. cit., p. 476. Emys gravis Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 626. Plate XXXIII, figs. 14-16. This species is known from a number of separated bones which were found together. It is probable that the pieces of carapace and plastron 144 THE WASATCH AND BKIDGER FAUNiB. belong to the same individual. The dermal sutural grooves are well marked. There is a large intergular scutum, which evidently encroached considerably on the mesosternal (a piece not preserved), and was probably subtriangular in shape. The gulars are reduced to triangular areas on the outer anterior angles, the suture with the humeral being in front of the middle point between the angle and the hyosternal suture. The margin is less distinctly emarginate at this suture than in Emys testudinea. The marginal bones belong to both bridge and free edge. They are all much thickened medially, but with thin proximal sutural margins. The free ones are Avell recurved, and with regular rather thickened margins. The bridge marginals have very obtuse margins, Their general massive- ness is in contrast to the thinness of the costals, of which there are numerous fragments. Portions of vertebral bones are intermediate in thickness. There is no thickening or ridge on each side of the vertebral scuta. The scutal grooves are everywhere well marked. The surface of the max-- ginals and episternal is obsoletely rugose, somewhat as in some species of Taphrosphys from the Cretaceous. The posterior marginal bones are stout and more thickened inferiorly than those of the E. vyommgensis and E. shaughnessiana, and are more re- curved. Measurements. M. Length of ppistenial (.approxiiii.ite) 04 Length from posterior suture (approximate) to gular scute 02 Thickness of episternal, behind CI 1 Length of a marginal bone 042 Width of same m.irgiunl bono 045 Thickness of same marginal bono Ol,"! Width of a bridgi--inarginal 04 Thicknetiss of a verbetrai 007 From the Wasatch beds of Wyoming, si.x miles north of Evanston, near Bear River. BAENA Leidy. Geological Survey Wyoming, 1870, p. :J67. Survey Montana, 1871, p. 368. Report U. S. Geol. Sorr. Terrs., Hayden, i, p. 160. Cope, Annual Ucport U. 8. Geol. Siirv. Terra., 1872 (1873), p. 621. Chit- tmium Leidy, Proceed. Acad. Thila., 1872, p. 162. This genus agree with the Adocidce* in the presence of intergular scuta and the absence of coossification of the ischium and pubis with the plastron, * Proceedings of the American Philosophicol Society, 1870, p. 547. TESTUDINATA. 145 but differs in the presence of an intersternal bone on each side, as in the Pleurodira. As generic characters it possesses two marginal intergular plates, which resemble the gulars of Emydidce. It has a series of inter- marginal scuta. The free lobes of the sternum are narrowed and shortened and the bridge is very wide. The dermal scuta are everywhere distinct. The mesosternal bone is in form between T-shaped and sagittate. The last pair of marginals, instead of being in contact, are separated by a wide emargination. The preceding characters were first noticed by Leidy. Another one appears in my specimens of B. arenosa, B. undata, and B. hebraica, which Dr. Leidy does not mention, viz, the presence of five costal scuta instead of four. The accessory one is anterior, and is taken from the usual first costal and first vertebral, both of which are contracted in consequence. Leidy's specimens are damaged in the region in question, and do not dis- play anything. The character is unique in the order Testudinata, unless it be found in the Platychelys of the European Jurassic, which is one of the Baenidx The afiinities of this genus are complex and interesting. It would be a pleurodire, but for the fact that the pelvis is not coossified with the plastron; nevertheless there are rudiments of this union in the form of a shallow pit on each side. The posterior or ischiadic is near the posterior end, and on the lateral mai-gin of the post-abdominal bone ; it is of a naiTow, oval form. The anterior is shallow and sublaterally impressed into the side of the upright septum which supports the carapace. Whether it received the pubis or not is uncertain. The double intergular scute is not found in any existing genus of Pleurodira, but exists in Tropidemys Riitim. of the Jurassic. The posterior margin of the carapace is excavated as in Chelydra, but the margin is more arched in this position. This form in Baena suggests the presence of a large tail, and the sen-ate margin of the carapace posteri- orly reminds one again of Chelydra. There ai-e in B. arenosa fourteen mar- ginal scuta without the nuchal; in Chelydra serpentina, as in Emydidce, but thirteen. There are prominent axillary and inguinal septa, as in some Emydidce^ 146 THE WASATCH AND T^UinGKK FADNiB. They are composed of the produced edges of two coossified costal bones, united with the ascending buttresses of the plastron. The affinities appear to be to Adocus on the one side and Hi/dra-npididie on the other, perhaps as descendant of the former and ancestor of the latter. It also possesses traces of the other relationships of Adocus, i e., to Dernia- temys, and more remotely to Chehjdra. Baena hebraica Cope. Baicna kehraica, Proceed. Amer. Philos. Soc, 1872, p. 463 (published July 29). Annual Report U. S. GeoL Sarv. Terrs., 1872, p. 621. Plate XIX, figs. 1-2. General form depressed and discoid, as wide as long. Bridge wider than long, but the length equal to the width of the bases of the sternal lobes. Anterior lobe longer than wide at the base, and narrowed at the extremity. The inguinal and axillary septa are very prominent. The edge of the carapace from the front to the inguinal region, is without emargina- tion. All the osseous elements are coossitied. The scuta are well distinguished. Tlie nuchal is very small and wider than long; the first marginal is shorter but more prominent. The second and third are larger but narrow; the fourth and fifth are wider, but the sixth widens by an inward projection of its border so as to meet the inter- costal suture between the second and third costal scuta. From this one to the ninth (as far as presei'ved) the inner margins are produced so far as to make the scuta nearly twice as wide as long when viewed from above. The first costal is small; its posterior border is curved. The first vertebral is pyriform, truncate in front. It is (perhaps abnormally) divided by a trans- verse suture into a quadrate anterior and cordate transverse posterior por- tion. The other vertebrals are somewhat longer than broad, and are sepa- rated by sutures convex anteriorly. The intermarginal scuta are all wider than long; their number is nor- mally four, but a narrow one is intercalated beliind the inguinal on one side. The longitudinal sutui-e of the scutes of the plastron is exceedingly tortuous, winding between points more than an imli apart. The gulars and intergulars ai'e transverse and bounded bv transverse sutures. They TESTUDINATA. 147 cross the median suture (which is straight ou the anterior lobe) some dis- tance apart. The humerals are long, and the humero-pectoral scutal suture is convex backwards, its extremities reaching the margin in front of the axillae. The anterior extremity of the anterior sternal lobe has a quadri- lobate outline. The surface is smooth except along the lines of intercostal sutures, where short grooves parallel to the general axis alternate with protuberances having the same direction, the whole having somewhat the appearance of sculptured characters. Measurements. ML Length of carapace (axial) (19 inclies).. .500 Widtli of carapace (axial) (19 inches).. .500 Length of plastron from groin 295 Width of base of anterior lobe 1,55 Width of extremity of anterior lobe (at gulars) 080 Length of anterior lobe (at gulars) 123 Width of nnchal scute Oil Length of nuchal scute 024 Length of third marginal 038 Width of third marginal 015 Width of eighth marginal , 090 Length of eighth marginal 063 This species, when compared with its nearest ally, B. undata, diifers in the greatly wider marginal scuta; in the latter the corresponding ones (6-7-8-9) are much longer than wide, as in most other tortoises. The intermarginal scuta are of more elongate form, and the normal number is five in B. undata instead of four. The sculpture in the longer known species is entirely distinct, consisting of pits and tubercles scattered gener- ally over the surface; while the peculiar sculpture of the suture lines is wanting. B. liebratca is relatively wider. Bad lands of Cottonwood Creek, S. W. Wyoming. BAiiNA UNDATA Lcidy. Annual Report U. S. Geol. Surv. Montana, 1871, p. 369. Cope, Annual Report U. S. Geol. Surv. Terrs., 1872, p. 622. Chistemum undatum Leidy, Report U. S. Geol. Surv. 1, p. 169, pi. xiv. Plate XIX, figs. 3-5. A specimen of this species presents the following characters: The anterior lobe of the plastron is as wide as that of B. hehraica, but little more 148 THE WASATCH AND BRIDGER FAUN^. than half as long. Tlie posterior lobe is truncate at the extremity. The nuchal scute projects beyond the first marginal ; the reverse is the case in the type of B. hebraka. The posterior sutures of the intergular and gular scuta have a common center, and that of the gular has a rectangular curva- ture, the nearly transverse middle portion slightly convex forwards. The suture separating the femoral and anal scuta is similar, but reversed in direction, presenting two obtuse right angles, two portions being transverse and one longitudinal on each side. The Baiina undata is quite similar to the B. arenosa in most respects. As in Leidy's specimens, the sutures of the plastron in the B. arenosa are obliter- ated in my single specimen, while in several of the B. undata they leave distinct traces even when coossified. As the latter are of larger size than the former, the diflference in this respect cannot be due to age. Besides, the plastron is smoother and presents no median carina. It is more roughened posteriorly with small irregular tubei'cular ridges. Traces of the grooves seen in B. arenosa are found on the anterior median region. The peculiar fifth or anterior costal scute is similar to that of B. arenosa, as are the gular and intergular scutes. In fact, the resemblances between this species and the B. arenosa are so close that I suspect that when we come to know the younger stages of the latter we will find that the intersternal bones are present, as in the B. undata. On this ground I have not adapted the genus Chisternum proposed by Dr. Leidy for the latter on account of the presence of the intersternals. Baena undata is more abundant in the Bridger beds than any other species of the genus. I found it on Black's Fork and elsewhere. Baena arenosa Leidy. Proceed. Acuo., 1872, j). .''>r>4 (October 12). Diplo- cynodm suhulatiii Copi', Annual Kriiort U. S. Geol. Surv. T«>rre., F. V. Hayilen iu ch.'irgf, ls72 (1873), p. 6i:t. Plato XXIV, figs. 5-19. Some of the cervical vertebrae without hypapophyses. Their cups round, with smooth bordering surface of the sides of the centrum. The jaws only are preserved from the cranium ; the premaxillary is strongly CROCODILIA. 153 pitted, but the dentaiy has remote shallow pits on the outer face, and shal- low grooves below. Dentition very characteristic. There are two very long canine-like teeth in the premaxillary bone near its posterior margin, directed somewhat backwards ; these are preceded, after a space, by a medium-sized tooth, which, after a similar space, is preceded by another long tooth. Ante- rior to this the alveoli are lost. Two very long, smooth, compressed straight teeth in the front of the ramus mandibuli. These are followed abruptly by a distantly set series of subequal teeth of not one-fourth the size, vary- ing little to the back of the jaw. All the long teeth have subcompressed crowns with opposed cutting edges, and are smooth except at their bases. These are sulcata with wide grooves, the separating ridges being acute. The smaller teeth are cones with cutting edges. There are fourteen alveoli and one pit in the dentary bone from the posterior end to the beginning of the short symphysis. Measurements. M. Length of alveolar series to beginniug of symphysis 130 Diameter of alveolus of seventh tooth 008 Elevation of eighth tooth 017 Diameter of eighth tooth at base 0065 Depth of dentary at base 025 Elevation of first lower cauiue 018 Length of crown of second upper cauiue 017 Diameter of crowu at base 007 Length of third cervical (with ball) 037 Diameter of cup, vertical 016 Diameter of cup, transverse . 018 Length of a posterior dorsal 041 Diameter of cup, transverse 026 Diameter of cup, vertical 022 Found on the bluffs of the Upper Grreen River, of the Bridger epoch. This species agrees in some respects with the very brief description given by Marsh for his Crocodilus liodon. He does not mention the fluting of the base of the crown so remarkable in this species ; and states the ver- tebrge to be "strongly rugose" near the extremity, a character not seen in the present animal. The Crocodilus suhulatus was about as large as the Mississippi alligator 154 THK WASATCH AND BUIDGEU FAUN^. Crocouilus polyodon Cope. Dijilocynodut polyodon Cope, Annual Report U. S. Geol. Surv. Terrs., F. V. Haydcn iu charge, 1872 (1873), p. til4. Plate XX^^^ figs. 1-2. Represented by portions of cranium and teeth, with probably some vertebrae found close to them. This crocodile is similar in size to the G. subulatus or our existing alligator. It differs much from the last in the arrangement of the teeth. There is one prominently lai-ge canine opposite the symphysis (in C. suhidatus this tooth is opposite the posterior end of the same), which is followed by nine very small teeth, whose round alveoli are only separated by very thin walls. Following the last of these immediately, is another very large tooth, with nearly round alveolus, which is closely succeeded by other smaller teeth of larger size than those in fi-ont of it, and not differing in this respect among themselves. The crowns of the teeth are cylindric at the base, and have a double ridge on the anterior outer aspect. The enamel is obsoletely nigose striate at the base. The external surface of the dentary bone is deeply and coarsely pitted ; at its anterior part the pits are close, deep, and small ; on the inferior face they are deep short grooves. There is a seines of close small foramina along the inner side of the alveoli. Measurements. M. Depth of symphysiii 014 Diameter of "anterior canine tooth" 008 Distance of same from median " canine" 030 Depth of dentary hone at latter 027 Width of ramus at anterior canine 025 This species differs in many respects from the one last described. The teeth anteriorly are much more closely placed, and the anterior and middle canines are less separated, and more numerous small teeth occupy the interval. The splenial bone has a larger share in the symphysis, and the sculpture is much more profound. The teeth are not fluted. The type specimen was found on the bluffs of Upper Green River by the writer. Crocodilus ackr Cope. Plato XXIII, figa. 1-2. This species is represented by a perfect skull wliicli Inoks the lower jaw. In its general form this skull resembles the existing Crocodilus acutus, CROCODILIA. 155 and is narrower than the C. elliottii and C. affinis. It belongs with the latter in the group with robust frontal bone with strong lateral ridges. The top of the muzzle is absolutely flat, transversely and longitudinally. In this respect it differs from the C. americanus, which is characterized by the presence of a strong convexity of the posterior part of the nasal bones, and the parts adjoining. The table of the skull is wider than long ; the orbits are convex inwards but not regularly, so that the outline of the inter- orbital part of the frontal bone contracts forwards. Anteriorly the orbits are angulate by the union of two oblique borders, the malar and prefrontal. The angle which is in the lachrymal bone, is continued as a shallow gutter for a short distance forwards. There are no crests on the head. The anterior extremities of the nasal bones are prolonged a short distance into the external nares. The jDostero-external angle of the squamosal bone is compressed. The undulation of the superior alveolar line is moderate, The external edge of the pterygoid bone is thickened and truncate. A considerable triangular area of the supraoccipital bone appears on the superior face of the skull. The premaxillary bone measured to its posterior apex, enters the length to the extremity of the quadrate bone, three and two-thirds times, or a little more than three times, to the posterior border of the cranial table. The palatine bones extend very little beyond the anterior boi'der of the inferior orbital openings, a character in which the O. acer resembles the C. affinis, and differs from the C. americanus* The pitting of the surface of the skull is strongly marked everywhere, except on a very small space at the junction of the frontal and nasal bones. Five pits may be counted across the middle of the interorbital front of the frontal bone. On this bone they are subround and not deep nor confluent, but are separated by ridges narrower than themselves. There are five premaxillary and thirteen maxillary teeth on each side. They present characters which readily distinguish them from those of any other species known to me. Their sizes are graduated, and the larger ones do not present an abrupt contrast of size, as in C. jiolyodon. Their ci'owns are all more or less compressed, and have distinct acute cutting edges. The compression is most marked on the last six of the maxillary * For fine specimens of this species I am indebted to the Smithsonian Institution at Washington. 156 THE AVASATCFI AND lUMOGER FAUN^. fieries, and the last four are short lancet-shaped. The crowns anteriorly are long and acute, but they begin to shorten with the fifth maxillary and diminish regularly posteriorly. Tlie basal portion of a fully protruded crown is smooth; the greater portion is, however, longitudinally grooved. There are eight ridges on the narrower and ten on the larger teeth. The grooves are not so deep, nor the ridges as acute as in C. sulciferus Cope, of the Bridger beds, and the crowns are less robust and not so incurved. The teeth of the present species have more acute edges. On these grounds I have been obliged to regard the C. acer as distinct from the C. sulciferus. Measurements. M. Length of skull to line of extremities of qnadiates ;i90 Leiii;lli of skull to posterior border of cranial table 345 Longlb of skull to line of anterior border of orbit 238 Width of preniaxiUary bones 060 Width at preuiaxillary notch 046 Width at fifth maxillary tooth 072 Width at anterior angle of orbits 058 AVidtli at posterior border of quadrates 19-J Width of iuterorbital space 021 '-mi., .■ L ■ ^ -ut , < tt'i'iporal foss.-B 090 Width of po8t of dorsal ] The skull of the second specimen has a resemblance in general to that of the Crocodilus affinis, but differs materially. The three most prominent points of distinction are the following : There is no distinct transverse ledge of the frontal bone between the orbits, and the space between the anterior parts of the latter is honey-combed like the posterior frontal region, and not smooth. Secondly, the posterior part of the squamosal bone, where it CEOCODILIA. 159 rests on the quadrate, is broadly truncate, instead of acuminate, and its postero-interior surface is subhorizontal, instead of vertical. Thirdly, the basal part of the angular process of the mandible is expanded inwards into a shelf with convex border. One or the other, particularly the first and second, of these characters have been verified on several individuals of the C. affinis. The general form of the cranium is much like that of the wider forms of the Crocodilus americanus. The front and top of muzzle are flat, and thei'e ai-e no crests or ridges on either. The maxillary border is strongly convex to the position of the posterior canine tooth, and is deeply notched to accommodate the inferior canine. The muzzle is shortened in fi-ont of the nares, since the premaxillary border descends steeply from their ante- rior margin. In consequence of the mature age of the individual, the sutures of the skull are obliterated. The united nasal bones project into the nareal opening for about one-third the long diameter. The orbits are somewhat narrowed by the convexity of the internal border of the malar bones. The interorbital space is plane, of course, excepting the sculpture, but there is a slight tendency to a transverse ridge about opposite the mid- dle of the orbits. The superior border of the quadrate condyle is deeply notched near the middle, to receive a corresponding angle of the mandible. The projecting angular process is very wide at the base, its superior surface having two concavities, of which the inner is nearly twice as wide as the external. The inner convex border contracts rapidly distally, leaving the obtuse free end a little wider than long, and directed inwards. The sculpture is roughly honeycombed on the superior surfaces, especially on the squamosal, post-frontal, frontal, and top of muzzle. On the middle line, posterior to the middle of the latter, the sculpture is reduced to a few longitudinal grooves, closely placed. The pits are much smaller on the borders of the maxillary and front of the maxillary. The rami of the mandible have longitudinal grooves on the external sides, and the anterior part of the chin has small pits. The symphysis of the mandible is like that of C. affinis, somewhat elongate for this genus, and produced and rather narrowed to the apex. The rami separate opposite the second tooth behind the notch of the upper 160 THE AVASATCn AND BRIDGER FAUN^. jaw. The lateral posterior foramen terminates anteriorly opposite the pos- terior border of the orbit. The anterior border of the palatine orbital foramen marks the posterior third of the distance between the orbit and external nares, on the top of the skull. The posterior border marks the posterior edge of the orbit. The pterygoid bones are produced and present backwards an acute external angle. The posterior nai-es are well behind the posterior border of the orbital foramina. The palatine bones are nar- rowed posteriorly between the orbito-palatine foramina, being at the middle of the latter, a little narrower than either foramen. The posterior maxilhuy and mandibular teeth are concealed in the specimen, owing to the closure of the jaws. There are four teeth in the maxillary between the canine and the notch for the lower canine. In front of the latter, in the maxillary bone, there are five teeth, of which the third and fourth, counting from the front, are largest. The teeth are all sepa- rated by short interspaces, and are graduated in sizes, the large teeth not being abruptly larger, as in C. polyodon. The crowns are robust, and with round section at the base. They have a low cutting edge \n front and rear. The enamel is roughened by numerous short crowded filiform ridges, as in many other crocodiles, which are worn off in old crowns. MeasuremenU of skull. H. Total length with angles of mandible 700 Length on superior surface ; parietal bono estimated .'>.30 Width between external angles of quadrates 300 Width at orbits 230 Width at superior canines lt>3 Width at superior notch 01'5 Widtli at middle of nares 130 Width between orbits 050 Width of nares 047 Length from end of muzzle to orbit 360 Length from end of muzzle to lino of canine 180 Length from end of muzzle to line of notch 100 Diameter of canine tooth at base 020 Length of symphysis maudibuli 115 Tlie ouly difference to be noted between the fragments of the upper jaw of the type specimen and the corresponding parts of this one, is to be seen in the premaxillary teeth. In the former they are larger and are not separated by as distinct interspaces; the third and fourth appear to have CROCODILIA. 161 been in contact. While the form of the symphysis of the mandible is the same in both, the ramus of the type is stouter. The vertebrae are mostly injured. A cervical has a simple anterior hypapophysis with a concavity on each side of its base, and an obtuse keel on the middle line behind it. The ball is nearly round, and is bounded by a strong shoulder. The external slope of this shoulder is marked by a few ridges, and by considerable rugosity at the base of the neural arch. In a dorsal, the ball is a little deeper than wide, and the middle line behind the hypapophysis is a keel. The ball of a lumbar is wider than deep, and the external border surface of its shoulder, as well as that of the cup, are rough with short ridges. The first caudal has a robust diapophysis, and a fossa on the median line below. The chevron facets are large. Measurements of vertebra:. M. Length of a cervical 160 Diameters of base of ball ^^'''^^'^='1 " ^^ c transverse 033 Length of a lumbar 061 Diameters of a lumbar^ vertical 0:J2 ( transverse 041 Length of first caudal 060 vertical 030 transverse 028 Diameters of ball < The right half of the pelvis is preserved, wanting the distal extremities of the pubis and ischium. It has the typical crocodilian character of the perforation of the acetabulum open anteriorly by the failure of contact between the pubis and ilium. The ilium is much like that of the Missis- sippi alligator, so much so as to render description superfluous. Measurements of pelvis. Length of ilium ". 160 Depth of ilium 092 Width of contact with ischium 035 Width of ischium at base 080 Width of ischium at middle 033 Width of pubis at base 040 Width of pnbisat middle 019 Two dermal bones preserved are probably from the lateral dorsal region, although this is not certain. One of them is large, the other small; both are oval in shape, the larger rather narrowly so, and neither have a dis- 162 THE WASATCH AND BUIDGER FAUNiB. tinct keel. Both have a slight median elevation in the short diameter. The fossae are rather far apart; edges smooth. Length of the larger "".085: width .045. There are traces of the sutures of the neural arches of the lumbar verte- brae, showing that the individual was adult, but not aged, at the time of death The only species with which the present one can be confused, is the C. aptus Leidy, which was founded on a cervical vertebra from South Bitter Creek, "Wyoming. In that locality the beds of the Wasatch and Green River formation occur, and probably the Bridger; those of the Washakie group are not mauA', perhaps fifteen miles distant. This vertebra belongs, according to Leidy, to the cervical series of an adult animal, and measures only 16 lines long. A vertebra of the C. clavis, which must coiTespond in position very nearly with the one described by Leidy, measures 27 lines in length, and is therefore between half as long again and twice as long. This indicates an animal of so much greater size as to render their specific iden- tity highly improbable. A crocodile occurs in the Washakie beds with the C. clavis, of which I possess a fragmentary skull. It is of a size appropriate to the vertebra typical of C. aptus. Crocodilus affinis Marsh. American Jouraal of Science and Arte, 1871, June. Plate XXI, figs. 1-3. This is the most abundant species of tlie beds of the Bridger basin. I took a nearly complete cranium with some vertebrae from a bad land bluft' on Smith's Fork of Green River; and my friend George Wilson, of Chey- enne, Wyoming, presented me with a considerable part of the skeletons of two individuals, including two nearly complete skulls from the Church Buttes. Fragments of others were found by various members of my party on Black's and Ham's Forks of Green River. I have pointed out the characters which distinguish this species from the C. clavis. Under the description of C. elliotii, Dr. Leidy loc. cit., has given a pretty full description of another near ally, so far as his material permitted. One readily observes that the frontal and j)arietul regions of the skulls CEOCODILIA. 163 of this species are less rugose than those of the C. davis, especially in the plane in front of the interorbital ledge. It is there absolutely smooth. Posterior to the bridge, the fossas ai'e frequently no wider than their inter- spaces, which is not the case in C. davis. The middle line of the posterior half of the muzzle is nearly smooth. The sculpture of the malar bones is very strong, and that of the superior middle of the maxillaries nearly as much so; that of the lower jaw is distinct. The form of the skull is Avedge-shaped, and it is flat above, without keels or crests. The "interorbital ledge" is an abrupt change of level, with an outline concave forwards. It is somewhat like the corresponding locality in the existing jacares of South America. The extremity of the premaxillary drops off abruptly from the nares. The outline of the upper jaw is sinuous; the orbits are vertical in direction. The posterior part of th« squamosal bone is narrow, with nearlj? vertical interno-posterior side, and acuminate extremity. The posterior edge of the quadrate condyle is emarginate. The angular process is rather narrow, and is obtusely rounded at the extremity. The lateral mandibular foramen extends as far forwards as the line of the middle of the orbit. The symphysis of the lower jaw is of medium length, reaching the seventh tooth from the front. The chin is wedge-shaped. The teeth of the upper jaw are : premaxillary, 5 ; maxillary, 4, the canine, and 11. The anterior teeth are elongate conic, with somewhat compressed crowns, and weak fore-and-aft cutting-edges ; the posterior ones have very short ci'owns. The enamel is finely and roughly striate. In the mandible the first tooth is larger than the two succeeding; the fourth is the very large canine; those following the canine have about half its diameter. In this part of the dentition the C. affinis is like the C. davis. The sutures are well preserved in one of the crania. The posterior part of the parietal is nearly as wide as that of the frontal. The anterior part of the latter is much produced between the prefrontals. The nasals extend backwards behind the apices of the prefrontals and lachrymals, and are continued forwards as an acute process into the external nostrils to the third of their long diameter, as in C. davis. 164 TOE WASATCH AND PRIDCKU FAUNiE. Meagurementu of skuU. M. Leugth to anf^les of mandible 500 Length to posterior iKtrdcr of iiarietals 370 Willi 1) hcuvteii cxtiTiial angles of (juutlrates 218 Width af orbits 180 Width of supeiior caniues 1'20 Width (if .su]iorior notch 060 Width of iiiiddle of nares 085 Width between orbits 033 Width of nares 030 Length from end of mozzlo to orbit ;ioO Length from end of muzzle to canine 120 Length from end of muzzle to notch 0G9 Diameter of canine tooth at base 015 Length of symphysis mamlibuli 080 The vertebrse preserved are five lumbars; four with centra nearly com- plete. They have nearly round cups, and the shoulder at the base of the ball is not so prominent as in the lumbars of C. clavis described. The edge of this and of the cup, is marked with distinct short longitudinal ridg'es. What characterizes these vertebrje as diflPerent from the lumbars of C. clavis is the presence of a wide open groove of the inferior median line of the centrum. The sides bounding these grooves are regularly rounded and not angulated. This fact, with the absence of chevron facets, satisfies me that these vertebrae are not caudals, which are always grooved below. Measurements of a lumbar vertebra. M. Length of centrum, including ball 041 _,. . , < vertical 022 Diameters of cup < . ^^ ( transverse 022 Elevation with neural spine 063 Expanse of prezygapojdiyses 049 In some of these lumbars the neurapophysial suture is obliterated, indicating the maturity of the individual. Professor Marsh distinguishes his C. affinis from the C. elliotti of Leidy by the shorter premaxillary bones and a few other characters. I find my crania to agree nearly with the former in the characters in question Crocodilus hetkrodox Cope. Sygtemotic Catalogue Vertebrata, Eocene of New Mexico; U. S. G. G. Survey W. 100 Mer., by G. M. Wheeler, 1^75, p. 34. Alligator hclcrodon Cope, Prooced. Amer. Philos. Soc. 1872, p. 544. Annual Report U. S. Geol. Snrv. Terrs., F. V. Ilayden, 1872 (1873), p. (il4. Plate XXIV, ligs. 11-18. The anterior and posterior teeth of this species differ exceedingly in shape; the former are fiattened, sharp-edged, and slightly incurved ; the CROCODILIA. 165 edges not serrate. Those of tlie premaxillary bone are subequal in size, while one behind the middle of the maxillary is larger than the rest. The posterior teeth have short, very obtuse crowns with elliptic fore-and-aft outline. They resemble some forms seen in Pycnodont fishes, and are closely striate to a line on the apex. The upper surface of the cranium is pitted, the frontal and parietal bones with large, deep, and closely-placed concavities. The former is perfectly plane and the latter is wide. The squamosal arch is also wide, and the crotaphite foramina are large and open. The dermal scuLa are very large for the size of the animal, and were not united by suture. They are keelless and deeply pitted, with smooth margins. The vertebral centra found with other specimens are round. The coossified neural arches indicate the adult age of the animal. Measurements. Height of crosvn of premaxillary tooth 004 Width of crown of premaxill.ary tooth at hase 0035 Long diameter of crown of a maxillary 005 Short diameter of crown of a maxillary 0035 AVidth of pariet.al 009 Width of frontal, posterior 020 Width of frontal, interior orbital 010 Width of m.alar below the eye 008 The variation in the form of the teeth is a slight exaggeration of that seen in the dentition of various species of crocodilians. The axial portion of the basioccipital bone is a transverse vertical plate with vertical carina on the distal half. The frontal bone exhibits no ledge or crests, and the crotaphite foramina are open. The quadratojugal arch is stout. The dermal scuta are not united, and with the cranium, are deeply pitted. They are very abundant in some of the beds of the Green River epoch. Some of them exhibit a faint trace of keel. Vertebrae asso- ciated with them have subround articular extremities. This is the smallest North American species, and is as small as any mem- ber of the genus that is known. It did not probably exceed three feet in length. I only found it in the beds of the Wasatch or perhaps Green River epoch, south of Black Butte, Wyoming. A species of similar proportions 166 THE WASATCH AND BRIDGER FAUNJE. left its remains in the Bridger beds, judging from vertobrnc wliicli I found on Black's Fork of Green River. A somewliat similar'sniall species is found in the Wasatch beds of New Mexico, the C. chamensis Cope. In that species the dermal scuta are articu- lated together by suture. MAMMALIA. The lacustrine Eocene strata have been found in all parts of the world, where existing, to contain remains of an abundant mammalian life. The character of this mammalian fauna has been found to be particularly inter- esting, and for the following reasons. Much light is thrown on the history of the Mammalia by the researches into the structure of those of the Eocene formation, and I deem it demon- strated to a certainty that the case with the mammals of this formation is the same as with the rej)tiles of the Permian, i. e , that the family types are all more generalized, and the orders not nearly so widely distinguished as in later periods of the world's history. The recent orders of fishes were in existence in the Cretaceous period, and probably earlier. Their period of evolution was in the Devonian and the Carboniferous periods. The existing orders of reptiles were all estab- lished prior to the Eocene; the period of evolution was the three Mesozoic ages, but especially the Permian. The orders of birds were inchoate in the Cretaceous, but when they were fully differentiated is unknown. The existing orders of Mammalia were already established in the Miocene period; during the Eocene they were in process of differentiation, and were less, or scarcely at all distinctly defined.* Tiie characters of the Placental Mammalian orders which existed during Eocene time are as follows: 1. Ungual phalaiiffcs cla\v.s (uuguiculate). a Cerebral heniispberes small ; cerebellum aud olfactory lobes large anil iincovcrfd. fi Teeth slu-atht'd in t-namt'l. Glenoid cavity longitudinal ; mandibular condj'le round ; anterior limbs ambulatory Rodentia. •Sci' Aiimml Report U. S. Gcol. Surv. Terra. 1872, \k G4,'>. MAESUPIALIA. 1 67 Glenoid cavity and mandibular condyle transverse ; anterior limbs constructed for flight Chiroptera. Glenoid cavity and mandibular condyle transverse; anterior limbs ambulatory Bunotheria. II. Ungual phalanges hoofs (ungulata). a Os magnum supporting the lunar and not articulating with the scaphoid. The astragalus articulating with the navicular only, and the cuboid with the calcaneum only Taxeopoda. (The astragalus articulating with the navicular only; cuboid articulating with distal faces of calcaneum and navicular. Prohoscidia.*) The astragalus articulating with the cuboid and navicular.. Amhlypoda. aa Os magnum supporting the scaphoid, and more or less of the lunar. Astragalus articulating with both cuboid and navicular Biplaethra. MARSUPIALIA. Although many of the Mammalia of the Lower Eocene formation re- semble the Marsupialia, few of them present chai'acters which are unques- tionably those of that order. They appear in many instances to possess characters of the Insectivorous and Carnivorous orders as well, so that it has been thought best to refer them to a single order in combination with the Insedivora, the Bunotheria. A few species, however, present the mar- supial facies so decidedly, as to leaye no alternative but to refer them to that order, until further evidence shall confirm or set aside such a conclusion. The two genera now to be treated of are not very nearly related to any existing form of Marsupials. The nearest ally of one of them at least is characteristic of the Jurassic age, and has been referred by Professor Marsh to a distinct order under the name of the Allotheria. As Professor Mai'sh does not offer any characters by which this group can be distin- guished as an order from either the Marsupialia or the Bunotheria, I have not been able to adopt it. As Falconer has suggested, their nearest ally is perhaps Hypsiprymnus among the existing Marsupials, and Thylacoleo has perhaps an equal affinity. As the only part of the structure of these genera which is well known is the dentition, I define them as follows. The family of the Plagiaulacidce differs from that of the MacropocUdce in the possession of but two inferior true molars. Most of the genera have the fourth pre- * Not known a8 Eocene. 1(38 THE WASATCH AND BRIDGER FAUN^. molar trenchant, and generally those anterior to it also, while in the Macro- pidce the trenchant premolar, if present, is the third. The genera diflFer as follows: a Several large cutting premolars. Premolars four, sides not riil;;ed Ctenacodon. I'reutohirs typically tliree, with oblique lateral ridges Plagiaulujc. a a One large cutting premolar. P Inferior molars large, with several tubercles. Large premolar without posterior cusp; edge directed upwards; sides ridged Ptilodm. a a a Fourth premolar rudimental or wanting. Large premolar with posterior cnsj); edge directed forwards; molars with two rows of tubercles Catopmlis. Fourth premolar? wanting; molars with three rows of tubercles Pohjmaxtodon. ,? ,? Inferior molars small, with few lobes; the last rudimental. Large premolar without posterior cusp; edge directed upwards; sides not ridged Thylavuko. Of the above genera, I'lagiaulax is represented by two species in the English Jurassic; Ctenacodon by two species in the North American Jurassic; Ftilodus by two species, from the Lower Eocene, one from France and one from North America ; Thylacoleo by one species from the Pliocene of Austra- lia; Catopsalis by two species from the Lower Eocene of North America; and Polymastodon by one species from the Lower Eocene of North America. The phylogeny of these forms in connection with that of the kanga- roos may be expressed as follows: It is evident that such forms as Thylacoleo^ Ptilodus, and Catopsalis are more specialized than Playimdax ami Ctenacodon, inasmuch as the number of teeth is reduced, and the cutting function of the premolars is concentrated in a single large tooth, or is obsolete. This is quite the same kind of specialization as that which has taken place in the history of the descent of the Carnivora. Ctenacodon, as having the largest number of premolars, which have the least amount of sculpture, is the least specialized of all the genera. Thylacoleo, with the rudimental character of tiie true molar teeth, is the most specialized, as it is the latest in time. The Alacropodida: retain the full series of true molar teeth of the ])riniitive jMammalia, and pre- sent only a cutting third premolar in the lower jaw, the fourth reseu)- bling the true molars. Thus the cutting tooth of Thylacoleo is not the homologue of the cutting tooth of Uypsiprymniis as suj)posed by Professor Flower;* since tlu- latter corresponds with the cutting tooth of Ptilodus, ' Quarterly Jonnml Gcologiciil Society, 1868, p. 307, vol.'zxiv. MAESUPIALIA. 169 which is the fourth premolar of Plagiaulax. We must therefore regard Hypsiprymnus as the descendant of a type from which the Plagiaulacidce were also derived, in which some of the premolars, as far as the third only, were trenchant, and in which the fourth premolar possessed the tubercular character of the three true molars. Such a type would belong to Jurassic and perhaps even to Triassic times, and might well have continued to the Eocene. I call it provisionally by the name Tritomodon. The lines of de- scent will appear as follows: Tritouiodoa (theoretical). / ^ Ctenacodou. / Plagiaulax. / ^ / Ptilodus. / Catopsalis. / Hypsipryinnus. / \ Thylacoleo. Macropus. The discussion between Professor Owen on the one hand, and Messrs. T'alconer, Kreflft, and Flower on the other, as to the nature of the food of Thylacoleo, is known to paleontologists. From the form of the teeth alone Professor Owen inferred the carnivorous natui'e of the food of this genus, while his opponents inferred an herbivorous diet from the resemblance between the dentition and that of the herbivorous Hypsiprymnus. As the result of the discussion affects in some degree the genera Catopsalis and Ptilodus, I recall it here. The comparison of Thylacoleo with Hypsiprymmis is weakened by two considerations: first, the fact that the cutting tooth of the former is not homologous with the cutting tooth of the latter; and sec- ond, that the grinding series of the former is rudimental, and in the latter it is complete. It evidently does not follow that because Hypsiprymnus is 170 Tin: WASATCH AND BRIDGER FAUX.E. lierbivorous, Thijlacolco is so also. Professor Flower refers to the absence of molars in ThylacoJeo as slifrhtly complicating the problem, and concludes that the food of that animal may have been fruit or juicy roots, or even meat. It is difficult to imagine what kind of vegetable food could have been apjiropriated by such a dentition as that of PtUodus and Thylacoleo. The sharp thin serrate or smooth edges are adapted for making cuts, and for dividing food into pieces. That these pieces were probably swallowed whole, is indicated by the small size and weak structure of the molar teeth, which are not adapted for crushing or grinding. It is not necessaiy to sup- |)0se that the dentition was used on the same kind of food in the large and the small species. In PtUodus medioEVUs the diet may have consisted of small eggs which were picked up by the incisors and cut by the fourth pre- molar. In Thylacoleo it might have been larger eggs, as those of crocodiles, or carrion, or even the weaker living animals. The objection to the suppo- sition that the food consisted of vegetables, is found in the necessity of swallowing the pieces without mastication. In case it could have been of a vegetable character, the peculiar teeth would cut off pieces of fruits and other soft parts as suggested by Professor Flower, but that these genera could have been herbivorous in the manner of the existing Macropodidcc, with their full series of molars in both jaws, is clearly inadmissible. CATOPSALIS Cope. American Naturalist, May, IStCJ (April 24), page 416. This genus is known from a part of a mandibular ramus with a few other bones associated. The jaw is broken off in front of the fourth pre- molar, and the fracture displays the shaft of a large incisor tooth. It is im- possible to state how many premolars there are. The fourth is of large size, and is exceedingly compressed. The alveolar border descends abruptly from its posterior root, having the outline of the diastema of the jaw in various rodents, where, however, it is edentulous. The result of this form is, that the crown is presented forwards in an acute edge. The inferior two- thirds of this edge is broken off, so lliat it is not possible to state whether it is grooved or serrate. The superior part is neither, mul rises into a cusp posteriorly. The two molar teeth are very peculiar, aiwl tlie first is much MARSUPIALIA. 171 larger than the second. The arrangement of the cusps is alternating on opposite sides of a median groove. The grooves are deep, and resemble the impression of a simply pinnate leaf with alternating leaflets. The coronoid process rises opposite the second molar. The inferior face of the posterior part of the ramus is flat, owing to both internal and external inflections. Both ai-e well marked, the latter bounding the masse- teric fossa, which is open in front, and without foramen. The internal in- flection bounds a deep fossa, like that seen in Hypsiprymnus and Macropus to terminate in the dental foramen. The only species of this genus known to me is from the Puerco horizon. Catopsalis foliatus Cope. American Naturalist, 1882, p. 416, April 24. Plate XXXIII c; fig. 2. The mandibular ramus which represents this animal is robust and deep. The alveolar line rises from behind forwards, as in Elephantidce and various rodents, and then suddenly descends. The inner side of the ramus is con- cave, while the external side, anterior to the masseteric fossa, is convex. The incisive alveolus is thus thrown inside the line of the molars in front. There is a large fossa exposed by weathering below and behind the last molar, which is identical with that seen in Hypsiprymnus and Macropus, and indicates a large dental foramen. Below the middle of the fourth premolar footh the incisor tooth is quite large, suggesting whether it had not a persistent growth, as in the Rodentia. The posterior cusp of the fourth premolar is triangular in profile, the ante- rior edge descending steeply. It is uncertain whether the edge of the crown rises again, forming another lobe. The apex of the cusp is conic. The first true molar is of large size and remarkable form. The crown viewed from above is a long oval. It has a deep median longitudinal groove, which sends out branch grooves alternately and at right angles to the edge. The spaces between the grooves form block-shaped tubercles, four on the inner and five on the outer sides, whose transverse diameter generally exceeds their anteroposterior. The median groove is open at its anterior extremity. 172 THE WASATCn AND DUIDGER FAUN^. The posterior is closed by an elevated convex margin. Tiie apices of the lobes are obtuse where not distinctly worn. The last (second) true molar is much shorter and a little wider than the first, and has the same character of surface. There are two large tubercles on the inner side and four small ones on the external side. The posterior end of the crown is narrower than the anterior. The anterior base of the coronoid i)rocess is opposite the posterior e.xtremity of the first true molar tooth. The jaw, with its denti- tion, in its present condition, has a curious resemblance to that of a tuber- cular-toothed Mastodon, witli the order of size of the molars reversed. Measurements. u. Length of base of true inol.irs 0166 Length of base of fourth premolar OlO(j Vertical diameter of root of incisor 0070 Diameters M. i J ""'•^■""P"*'^'"'"'" ^^^' ( transverse OO.'.O Diameters M. ii ^i-'t'T'.posterior 0060 ( transverse OOIM Depth of ramns at front of P-ni. iv 0120 Depth of ramus at front of M. i 0190 Depth of ramns at posterior eilge of .M. ii Ol.'O Width of ramus below P-m. iv 0070 "Width of inferior face of ramns below M. ii 0110 Found by my assistant, D. Baldwin, in the Puerco Formation of North- western New Mexico. PTILODUS Cope. American Naturalist, ISBl, November, p. 921 (October 28). Dental formula of infeT-ior series; I. 1 ; C 0; Pin. 'J; M. 2. Incisor occupying- a deep alveolus and probably growing from a persistent pulp. It forms an arc of a circle, with an anterior enamel band. First (third) premolar rudimental. Second (fourth) premolar disproportionately large, with compressed crown with a convex cutting edge, and lateral ridges di- rected upwards and posteriorly. Molars small; the first longer tiian wide, its crown divided by a deep longitudinal median groove into two lateral ridges, which are divided into lobes by transverse fissures. Tlio masseteric fossa is well marked. The intcnial pterygoid fossa is very deep and termi- nates in the foramen dentale, and is bounded below by a horizontal iuHection of the inferior border of the mandiltiil.ii- minus. MARSUPIALIA. 113 The characters of the fossre of the mandibular ramus are those of the marsupial order, and much like those of the family of the kangaroos. The absence of connection between the masseteric and pterygoid fossfe at the dental foramen distinguishes Ptilodus from that famil}^ The differences in the dentition have been already discussed. The announcement of the discovery of this genus in the Eocene forma- tion was a circumstance of much interest, and it has shown how persistent the type of the Plagiaidacidce has been. It is true that no representative of the Plagiaulacidce has yet been obtained from the beds of the Cretaceous period, which represent the long interval of time which elapsed between the Jvxrassic and the Eocene. We will not, however, on this account permit the supposition that they did not exist at that time. The existence of the Plagiaidacidce in the Eocene period v/as first ascer- tained by Dr. Victor Lemoine, of Reims, France, and was announced to the Geological Society of France at its meeting of January lO, 1881, and pub- lished in its Bulletin for 1881, p. 1G8, for May. This announcement had escaped my observation when six months later (October) I published the account of its discovery in New Mexico. I, at that time, gave the genus the name of Ptilodus, and I am not aware that Dr. Lemoine has yet printed any name, either generic or specific, for the form discovered by him. Ptilodus medt^vus Cope. Aniericau Naturalist, ISKl, p. 9'21, November; (published October 28). Plate XXIII c; fig. 1 This species is represented by two mandibular rami of probably the same animal, one of which lacks the part anterior to the premolars, and the other the part posterior to the premolars; by a single fourth premolar tooth of a second individual; and by all the inferior molars of a fourth. The ramus is short, and is deep posteriorly ; anteriorly its depth is re- duced by the concavity of the surface at the diastema, as in most rodents. The inferior border is i-ather thick anterior to its posterior expansion. The symphysis is not coossified. The incisor tooth is quite slender, and its sec- tion is a vertical oval, a little flattened on the inner side. The enamel band covers less than two-fifths of the face of the tooth, beginning with the inner 174 THE WASATCH AND BRIDGER FAUX.^. edge of the anterior face and extending externally. Its surface is entirely smooth. The diastema is moderately long. The first premolar is a very small tooth and has a single root. The crown is conic, and is pressed against a narrow truncate face of the base of the anterior edge of the fourth (second) premolar. Tiie vertical section of the fourth premolar is wedge-shaped, and the profile of the crown is regularly and strongly convex. The anterior root has a greater anteroposterior diameter than the posterior root, and the enamel extends further downwards on it than on the posterior root, on the external side; on the internal side this expansion is not so marked Tlie enamel of the sides of the crown is thrown into parallel ridges, which are gently curved, and which extend upwards and posteriorly to the edge, ex- cept at the posterior border, where they fall a little short of the edge. When they reach the edge the latter is angulate, forming a serrate outline. There are twelve ridges from front to rear, and the anterior ones are closer together than the posterior, the widths of the interspaces increasing in regular pro- gression. The first true molar is very small, absolutely and relatively, its length being one-third of that of the two premolars together. The outline of the crown is elongate oval longitudinally placed. The median groove is wide, and is open at both extremities. The lateral lobes have continuous longitudinal acute edges, and number four on each side. The posterior lobe is twice as long as any of the others on botli sides, and its edge is weakly notched. No cingula. The alveolus of the anterior root of the second molar indicates a rather wider tooth than the first molar. The anterior border of the masseteric fossa is a strong ridge, and passes the alveolar border at the posterior edge of the first true molar. The fundus of the internal pterygoid fossa is deeper or more external than the line of the molars, falling below the external edge of the anterior masseteric ridge. Measurements. M. Length of ramns to last true molar inclusive (hJ05 Diaiui-ters M. i 5 ""t'^roposterior 0040 ( f rnnsviirHC 0020 1 aiitLTopostcrior 0085 Diaiiietfr8 P-m. iv ? IraiisviTsc at l)ase 0030 ( vertical at middle 0045 EODENTIA. 175 M. Length of diastema 0060 T^ .„ . . . < anteroposterior 002(! Diameters incisor < '■ < transverse 0020 Depth of ramus at diastema 0070 Depth of ramus at middle of P-m. iv 0000 The length of the skull of this animal was about equal to that of the Norway rat Mus decimianus, but the large proportions of the fourth premolar indicate that the cranium was much deeper than in that animal, and had probably the form of that of the Thylacoleo carnifex* RODENTIA. Remains of species of this order are not abundant in the beds of the Wasatch epoch, and are rather common in those of the Wind River and Bridger. They are not very i^arious as to type, and the greater number are apparently allied to the squirrels. PLESIARCTOMYS Bravard. Plesiaretomys Bravard, Ossemens fossiles de Desbruge, 18r)0, p. 5. — Gervais, Pal^ontologie franjaise exijlic, tab. 30, p. 4. Paramys Leidy, Report U. S. Geol. Surv., 4to, i, 1873, p. 109; Proc. Pbila. Acad., 1870 (name only). Pseudoiomus Cope, Paleontological Bulletin No. 2, p. 2, August 3, 1872, nomen nudum; Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 610 (defined). The inferior molars by which this genus has been generally known resemble much those of existing Sciuridce, but there are cranial characters which distinguish it from the existing forms of that family. The crowns of the inferior molars support four rather small and strictly marginal tubercles, which inclose a median valley. The anterior inner tubercle is more elevated than the others, and the posterior -two tubercles are connected by a low ridge on the posterior border, which may be more or less tubercular on the last molar. In some of the species, the marginal tubercles are merely elevations of the margin, while, in others, the adjacent tubercles of a pair approximate, so as to form a pair of interrupted cross crests. There are five superior molars, of which the anterior is of small size. They resemble tliose of Sciurus, but the transverse crests are obsolete or *A restoration of the skull of this animal is given by Flower, Quarterly Jonrn. Geolog. Society, vol. xxiv, 1868. 176 THE WASATCn AND BEIDGER FAUN^. wanting:. The positions coiresponding to their extern.al extremities are marked by more or less distinct cusps. There is a single internal tubercle of the crown. In the third and fourth molars of P. deUcatissimns I observe rudiments of a second internal tubercle. The incisor teeth are compressed, with naiTOw anterior face. The enamel is not grooved, and is little or not at all inflected on the inner side of the shaft, while it is extensively so on the external face. There is a large, round foramen infraorhitale exterins, like that of Ischyromys and Fiber, and entirely unlike that of Gymnoptychus and Sciurus, conforming in this respect to the forms of the extinct group of the Protoniyides of Pomel. The cranium of the specimen originally described by me as Pseudoto- mus hians, exhibits the following characters: The superciliary margin is short, and without jiost-frontal process. The temporal fossa? are large, and contract the brain case behind the orbits to a striking degree. Their ante- rior margins rise from the post-frontal angles and converge backwards, meeting in a sagittal ridge opposite the anterior part of the squamosal bone. The parietal bones increase rapidly in width to the squamosal, which are largely inferior at their zygomatic portion. They do not extend very far on the superior aspect of the skull, nor backwards beyond the auditory meatus. The occipital region is concave, and sun-ounded by a prominent crest The foramen infraorbilate exterius has an inferior position, being a little above the alveolar border. Tliere is a prominent tuberosity on the under side of the basal front of the malar bone, just exterior to the position of the second molar of Ardomys ; its inferior face is truncate. The pterygoid laminaj are jjrolonged, inclosing a trough. Their sphenoid ala? descend steeply from their posterior base, and have an external ridge, which marks out a pterygoid fossa. The otic bulla is not large. Paroccipital process distinct. T\\q foramen ovale is large, and is divided by a thin bridge of bone. The two external foramina resulting are also the alisphenoids. There are no additional foramina in this region. The space for the otic bulla is moderately large; the basicranial axis is grooved at the junction of the basioccipital and sphenoid bones. The zygomatic arch is deep and thin. The glenoid cavity is wide but longitudinal. The cast of the brain indicates smooth oval hemispheres, which leave RODENTIA. 177 the cerebellum and olfactory lobes entirely exposed. The latter are ovoid and expanded laterally. The coranoid process of the mandible is large and high, as in Arctomys. The condyle is small and compressed. The angle is produced, so that the posterior border of the ramus is concave. Associated with the skull of a P. delicatissimus are various parts of the skeleton. A lumbar vertebra is not elongate ; its anterior articular face is slightly convex and the posterior plane. The outline of the former is a little more than half a circle. The diapophyses are large, and are opposite the floor of the neural canal. The prezygapophyses are subvertical, and the superior exterior edges are developed into well marked metapophyses. The middle line below has a low narrow keel, which separates two large nutritious foramina. The proximal part of the scapula is preserved. It resembles in gen- eral that of a squirrel, having a recurved coracoid process, and a well developed acromion. The latter is quite flat, and is continuous with a hori- zontal expansion of the spine. The humerus has a subround head, and the tuberosities are little prominent, and enclose but a shallow bicipital gi-oove. The deltoid crest is prominent, and extends to the middle of the shaft. Its inferior portion is more prominent and compressed than the superior por- tion. The teres facet is well marked. The distal end is transversely extended by the large size of the internal epicondyle. The condyles are simple hour-glass-shaped, and without crest. The epitrochlear foramen is distinct. The ulna and radius are long and slender, and their carpal arti- cular surfaces are of subequal size. The head of the radius is nearly round. Two metacarpals are preserved, and they are rather short ; there is an inferior trochlear keel of the distal articular extremity. The pelvis is much like that of a squirrel. The ilium is not much expanded towards the crest, but cannot be called prismatic. Its external rib is near the anterior border, and the posterior edge is thin, and bounds a concavity of the external face. The anterior inferior spine is prominent The ischium is two-thirds the length of the ilium, and is moderately expanded distally in a vertical plane. Its spine is distinct Fragments of femora, associated with the other specimens, have the characters of those 178 THE WASATCH AND REIDGEU FAUN^. of the SciuridcE. The great trochanter is about as high as the head, and bounds a large fossa. The little trochanter is well developed. The rotular groove is moderately elongate, with nearly equal bounding keels. The condyles are subequal and present posteriorly. The distal extremity of the tibia supports an internal malleolus which is flat on its inner side, and is without distal facets. The external trochlear groove of the peronealy is larger than the internal. The posterior border is produced downwards in a subangular process as in other iSciurida; which is as long as the malleolus, and is openly grooved to carry the tendon of the flexor longus polUcis mus- cle. It is separated by a deep notch from the internal malleolus, through which passed the tendons of the flexor longus digitorum, and the tibialis pos- ticus muscles. The astragalus also resembles that of a squirrel. The head is du-ected inwards from the anteroposterior axis of the troachlea, and has a depressed and convex distal extremity. The trochlea is wide, and the groove is well marked. Its external and internal faces are vertical. The calcaneum is large, and the free portion is compressed. The sustentaculum is small. The species from which most of the characters of the genus as above stated have been derived are the P. delicatior and P. delicatissimus. They display the following general points. The. anterior limbs are relatively longer than in recent species of squirrels. The bead of the radius is rounder, indicating an unusual power of rotation of the anterior limb. The pelvis is larger, being as long as the skull, and it is probable that the posterior limb is larger. These points indicate approximation to the Mesodotda. No characters have yet been oflfered by which to distinguish the Ameri- can species as representing a genus distinct from the Plesiarctomys gervaisii of the French Eocene. Bravard briefly distinguishes the genus as distinct from Ardomys in the greater thickness of the angles of the molars, which thus become tubercles. Only the mandible and mandibular teeth of the P. gervaisii are known. It has been idund in thf Tppi r Eocene, near Perreal, Apt, France. I have seen five species of this genus, of which one, P. liiaua belongs to the Bridger beds ; one, P. leptodus, to the Washakie ; one, P. buccafus, to KODENTIA. 179 the Wasatch and Wind River, and two, P. delicatior and P. delicatissimus, to all the Eocenes except the Washakie. Plesiarctomys bucuatus Cope. Report U. S. Geol. & Geog. Expl. Surv. W. 100th Meridian, G. M. Wheeler, iv, pt. ii, p. 171 ; pi. xliv , fig. 8. Plate xxiva, fig. 14. Jaws of four specimens which agree in proportions with those of this species found in New Mexico, were obtained by Mr. Wortman in the bad lands of the Big Horn basin, Wyoming. The species was established on a maxillary bone bearing teeth, while the present specimens are all mandibles. I do not detect any difference between these and the lower jaws of P. delicatissimus, excepting the inferior size of the former, from which, however, the first and last molars are wanting. I give the following measurements : Measurements. M. Length of inferior molar series 1 ~ 012 Length of base of last molar 0038 Diameter of inferior incisor 5 '^"tero-posterior 0033 transverse 0008 Depth of ramus at second molar 0088 Plesiarctomys delicatissimus Leidy. Cope, Report U. S. Geog. & Geol. Expl. Snrv. W. of 100th Mer., G. M. Wheeler, iv, pt. ii, p. 172, pi. xliv, figs. 9-12. Paramys deUcatissimus Leidy, Proceed. Acad. Phila. 1871, 231 ; Report U. S. Geol. Sui-v. Terrs, ii, p. Ill, pi. vi, figs. 28-9. Plate xxiva, figs. 1-10. Poi'tions of the mandibles of four specimens of this rodent were brought by Mr. Wortman from the Wind River Basin ; also, the skull of another individual, and the greater part of the skeleton with the skull of a sixth individual. The specimen last mentioned furnishes the following characters. The skull has much the form of the large arboreal squirrels of the present day. The muzzle is of moderate length, and the zygomata are not very widely expanded. The skull is contracted just behind the eyes, for the orbits are not defined posteriorly. Above the eyes the superciliary border is angu- lar, but not prominent, and each one is continued as a delicate anterior tem- poral ridge. The ridges converge backwards and unite into a low sagittal crest opposite the anterior angle of the squamosal bone. The anterior supe- 180 THE WASATCH AND BRIDGER FAUN^. rior angle of the malar bone forms the inferior half of the anterior border of the orbit, but its inferior part is supported by a peduncle of the maxillary bone. Its posterior angle extends as far posteriorly as the external border of the glenoid cavitv. The occiput is vertical, and is wider than deep. It is convex in the position of the vermis, and concave on each side above the occipital condyle. The condyles are rather small, and are widely sepa- rated, bounding a very large foramen magnum. Inferiorly the basiocci- pital is flat in front of the condyles. Between the otic bullae it has a median keel, with a concavity on each side, bounded externally by a prominent desceiuling border in contact with the bulla. The massateric fossa of the mandible reaches the line of the posterior border of the penultimate molar tooth. The articular service of the condyle is nearly round, and is strongly convex, and projects as far backwards as a vertical line drawn from the angle. The coronoid process is much higher, and has a wide summit with a convex border. (^f the superior molars, the apex of the minute first is bifid, one cusp being the larger ; the second is a little narrower than the third, and the fifth is a little wider antero-posteriorly. The enamel is smooth on all the teeth in both jaws, including the incisors, and there are no cingula. "^riie extremities of the coracoid and acromion are about in one hori- zontal line. The former is abruptly turned backwards and truncate on the external face. The ulna and radius appear to have lost their epiphyses ; allowing for this, they are a little longeithan the humerus. The shaft of the ulna is rather compressed, while that of the radius in round in section. The distal expansion of oach is about equal. The trnclianteric fossa of the femur is very deep, and the little trochanter is very large. The third trochanter is represented by a low ridge. The distal extremity of the tibia has nearly equal anterojjosterior and transverse diameters, and the shaft at the distal two- fifths the length is nearly round. Mcasuremenis of No. 6. M Length of skull to lateral border of external nares to parocoipital process (ITOO Length from lateral edge of nares to orbit 02Q0 Lengt li from anterior border of orbit to posterior edge of zygomatic fossa OIKH) Length from posterior border of superior incisor to tlrst molar 0170 KODENTIA. 181 M. Le.igth of superior'molar series 0145 Length of molars II ami III together 0065 Length of molars IV and V together 0070 Transverse diameter of M. II 0042 Transverse diameter of M. V 0035 Width at eyes 0165 AVidth behind eyes 0100 Length of mandibular ramus from incisor to condyle 0400 Length of diastema 0060 Length of molar series 0135 Dejith of ramus at second molar 0100 Depth of ramus at coronoid process 0310 Depth of ramus at condyle 0235 Length of humerus (Nos. 5 or 6) 0600 _ . , ,. ^ „, ( anteroposterior of head 008 Proximal diameter oi humerus/ ..,,,,.. „, , ( transverse, with tuberosities Oia Distal, with humerus 016 Width of distal condyles of humerus Oil „. ^, , „ ,. (vertical 006 Diameter of head of radius < . „„, I transverse 007 Depth of radius (f minus epiphysis) 048 Depth of ulna at coronoid 006 Anteroposterior diameter of head of femur 009 Transverse diameter at little trochanter ■ 0135 Transverse diameter below little trochanter 009 Transverse diameter at distal end 016 Vertical diameter at distal end (greatest) 015 Diameter shaft of tibia at distal two-fifths of length 006 „ ,. , , ^ ., . (anteroposterior 010 Diameter at distal end ol tibia < , „,„ ( transverse 010 „. „ ,, „ . , (anteroposterior 008 Diameter of trochlea of astragalus ; , „„_ ° ( transverse 007 Length of head of astragalus 005 Angle of axis of head with trochlea 9° „. ^ „ • 1 r (vortical 0045 Diameters oi navicular race < ^ „„^„ ( transverse 0066 Length of a metatarsal 029 Length of ilium to acetabulum 0785 at crest 0150 I at acetabulum 0105 Vertical diameter of acetabulum 0105 Length of ischium 0128 ,„.,,, .. ,. ( at acetabulum 0075 Widths of ischium < ,,.,,. , „,^n I at distal border 0150 From the above measurements the following comparisons with the Sciu- rus niger may be made : The pelvis is longer as compared with the bones of the fore leg. The humerus is longer as compared with the length of the ulna and radius. The species exceeds the 8. niger in size, one-fourth linear. 182 THE WASATCn A^TD BRIDGER FAUN^. Plesiabctomys delicatior Leidy. Cop«, Report U. S. Geog. & Gool. Expl. Surv. W. of 100th M.r. G. M. Wheeler, iv, pt. ii, p. 172. Para- myi deUcati<»r Leidy, Proceed. Acad. Phila. 1B71, p. 231. Report U. S. Geol. Surv. Terrs. ISTJ, i, p. 110, pi. vi, Ugs. '2(>-7, pi. xxvii, tigs. 16-18. Plate xxiva, tigs. 11-13. This squirrel is represented by the jaws of at least four individuals in Mr. Wortman's Wind River collections. Two of these are further repre- sented by other portions of the skeleton, one of theiu including a maxillary bone with four molars in place. The bones of the skeleton coincide with the teeth in their superior dimensions as compared with those of the P. delicatissimm. The pieces of the last-named individual which are preserved are portions of the femur and tibia, with astrogali and calcanea ; also, portions of ulna and metatar- sals and ribs. The only difference of form I observe between these and corresponding parts of P. delicatissimus is in the distal extremity of the tibia ; This has a relatively greater transverse diameter as compai-ed with the anteroposterior than in the species just named. The calcaneum of the right side is nearly perfect. The free portion is strongly compressed ; the anterior portion appears depressed on account of the extent of the sustenta- culum on the inner side, and the well-developed corresponding process on the external side opposite to it. The cuboid facet is, however, as deep as wide, and truncates the calcaneum transversely. The external astragaline facet is very convex, and presents inwards and a little forwards. The superior molars accompanying, this specimen are of the size and proportions of the inferior molars, but they belong to the Mesodont, Pehj- codus frugivorus, described later in the present work, where the distinction between the molar teeth of this genus and those of Pelycodus are pointed out. Measurements. M. Length of inferior molar series 016 Length of last inferior molar 005 Longlh of diastema 0085 Depth of ramus at ponultimute molar 0115 Diameter of shaft of tibia two-fifths distance from extremity 0073 „. ^ /■ • • r .t ■ (anteroposterior 0095 Diameters of extremity of tibia? \ f riinsverse 01 10 antemposterior 009O Diameters of trochlea of astragalus \ traasverbo OOSO EODENTIA. 183 M. Length of head of astragalus 0055 Diameters of navicular face of astragalus )^ nnon ( transverse OUoO Depth of heel of calcancum at base 0080 Depth of cuboid facet of calcancum at base 0057 Width at susterotaculum 0132 Plesiaectomys leptodus Cope. Faraniys leptodus Cope, Paleontological' Bulletin, No. 12, \i. 3, March 8, 1873. Plate xxiv, fig. 1. Established on a right mandibular ramus with all the teeth preserved. It indicates an animal of about the size of the P. delicatus Leidy, but with smaller incisors, which have little more than half the diameter of the same tooth in those species. The molars have two anterior separate, and three posterior contiguous cones, the median smallest, the anterior and posterior of both sides separated by a deep excavation. The anterior tooth is pecu- liar in its greater compression. The posterior tubercles are not separated, and the anterior inner is situate behind the outer, and is connected with the posterior inner by a concave ridge. Measurements. If. Length molar series 0221 Length M. IV 0060 Width M. IV 0055 Length M. I , 0060 Width M. I 0048 Diameter lower incisor, transverse 0024 Diameter lower incisor, anteroposterior 0038 From the South Bitter Creek, Wyoming, from the Washakie Basin. Plesiaectomys hians Cope. Pseudotomus hians Cope, Paleontological Bulletin No. 2, p. 2, 1672. Annual Report U. S. Geol. Sury. Terrs., 1872, p. 611. Plate xxiv, figs. 3-5. This species was established on a nearly complete cranium, from which some parts of the walls are broken, and only the anterior portion of the mandible remains. It belonged to an old individual which had lost its molar teeth, and whose inferior incisors are very much worn. The cranium is of depressed form, and with considerably expanded 184 THE WASATCIJ AND liKID(iEK FAUX^. zygomata. The muzzle is broad and but little elevated, so that the nasal meatus is between the alveolae of the superior incisors. The enamel of the superior incisors is not grooved, but has a delicate striate sculpture. The inferior incisor does not project as far as the alveolar border of the jaw, its surface worn by the upper incisor is horizontal and anterior. The inferior diastema is a thin edge, and the ramus is deep there. The temporal surface of the parietal bones is rugose. The cranium is depressed, and has a trace of sagittal crest. The anterior margin of the temporal fossa is marked by a curved angle on each side of the frontal bone. The supra- orbital arch is very short. The mandibular incisors ai'e narrowly separa- ted by a naiTOW prolongation of the symphysis. The exposure of the tooth is lateral, its direction nearly anterior. It projects anteriorly very little beyond the symphysis, and has a horizontal triturating surface below the level of the latter. There are alveolae for but three molar teeth, each with three roots. The teeth themselves are not contained in them, but were apparently lost before the cranium was entombed in tlie Eocene mud. The position of the first molar is occupied by spongy bone in both maxil- laries, and appears as though such teeth might have existed eai-lier in life, and been shed. Measurements. M. Longth of cranium (3.75 in.) 095 Width of cranium (without zygomas) 040 Width of cranium (with zygomas) 072 Width of occiput 032 Width of occiput near end of nasals . 027 Width of ui)pcr cutting tooth 007 Depth of upper cutting tooth 0085 Length exposed i)art lower tooth 009 Width exposeil i)art lower tooth 006 The species differs from the P. delicatus Leid}', in its superior size, being, in fact, the largest species of the genus. The typical specimen was found by myself on Cottonwood Creek, Wy- oming, in the IJridger beds. BUNOTHERIA. 185 BUNOTHERIA. This division embraces the imguiculate Mammalia of low cerebral development, which have the transverse articulation of the lower jaw, and ambulatory limbs. It embraces a series of types which present a great range of variation in dental characters, but which at the same time pass into each other by sensible gradations. I^js jpossible th at some o f the types whichXtave referred here may turnj)ut to be Marswpialia^ hut jhe^ number of such cases is pro bably s piall. . The following is the definition of jhisj)rderi- Cerebral hemispheres small, leaving the olfactory lobes and cerebelum exposed ; the surface smooth, or nearly so. Limbs ambulatory, armed with a greater or less number of compressed ungues. Articulation of the mandi- ble transverse. Molar teeth of the superior series (and usually ot the lower) tubercular, and without continuous crests. Incisor teeth present in the premaxillary bone. Teeth invested with enamel. Feet with five digits (with a few exceptions). Usually a third trochanter of the femur. I once applied to this order the name Insedivora, so as to avoid the creation of a new one, but I subsequently concluded to adopt the latter course as the preferable one. The name Insedivora has acquired currency as applied to the well-known modern group of that name, and its applica- tion to types of such apparent diversity as those now associated under a single head is not a convenience. I therefore proposed the name Bunotheria for the order, and included under it the suborders Creodonta, Mesodonta, Insedivora^ Tillodontu, and Taeniodonta* I suspect that the Prosimice must also be included in this order. The suborders are characterized as follows: Superior incisors normal, not growing from persistent pulps; canines much enlarged ; premolars compressed ; molars more or less sectorial ; astragalus generally not grooved above, articulating with cuboid and navicular; scaphoid and lunar bones (? always) distinct Creodonta. Incisors not growing from persistent pulps ; molars tubercular, never sec- torial ; third trochanter elevated ; astragalus not grooved above Mesodonta. Incisors enlarged, simple, not growing from persistent pulps, canines re- duced ; astragalus concave above Insectivora.i * Report of Lieut. G. M. Wheeler of the Expl. Surv. W. 100th Mer., iv, 1877, p. 72. tThe typical Intectivora, Linn., Bonap., Gill. 186 TnE WASATCH AND BRIDGER FAUN^. Incisors much eularged, growing from persistent pulps, and faced with enamel in front only ; therefore scalprifonn Tillodonta. Incisors much enlarged growing from persistent pulps, the superior with enamel in anterior and posterior bands, and hence truncate Taniodonta. The order of JBunotheria with tliese subdivisions, is not more heterogene- ous than that of the Marsupialia, and presents a great similarity in its com- ponent parts. Thus the Creodonta resemble Sarcophaga, the Insectivora the Entomophaga, and the Tillodonta the Bhizophaga. Fhascolamys, the type of the last suborder presents several points of resemblance to the Tillodonta. The affinities of the groups here combined under one ordinal caption are very divergent. The order is generalized, and, as such, does not present the peculiar features of the Chiroptera, Modentia, and Edentatu, but is so far negative in its character as to preclude more than subordi- nate subdivision. While the existing division Insectivora maintains the typical characters, the Dermoptera, also existing, are doubtless relics of the group from which the Chiroptera derive their ancestry. The Tillo- donta exhibit some kind of affinity to the Rodents, while the Tceniodonta present us with a point of connection with the Edentata. The discovery of this fact was particularly welcome, as we had not previously had any hint of the relations between that anomalous order and the remainder of the Mammalia. So far the relationships indicated are to smooth-brained (lissencephalous) orders only. The connections with the Gyrencephala (or Educabilia) are quite as close; namely, as already pointed out, through Me-so- donta to the Prosimice and the Quadrumana, and through the Creodonta to the Carnivora. Standing in this structural relation to different existing types, and in an antecedent relation as to time, it is easy to look on the Bunotheria as ancestral to some of them. In the first place, the Insectivora represent them in the existing fauna. The Creodonta are probably the ancestors of the Carnivora, and the Mesodonta of the Prosimiel face of the second incisor is thrown into shallow longitudinal grooves with more or less numerous irregularities, from the low dividing ridges. There is a deeper groove on each side of the tooth, and there are about a dozen ridges between these on the anterior face. Both cusps of the first premolar are conic, and the exter- nal is the larger. The second true molar is a little smaller than the first. The enamel of the premolars and molars is smooth, and there are no cingula. Probable length of dental series .0750; diameters of I. 1: anteropos- terior .0120, transverse .0066; diameters I. 2: anteroposterior .0160, trans- verse .0115; diameters Pm. 1.: anteroposterior .0072, transverse .0130; di- ameters of M. 11: anteroposterior .0090, transverse .0090. Length of true molars .003b; depth of ramus at M. 11. .0360. The short deep jaws of this animal must have given it a very peculiar appearance, not unlike that of a parrot in outline. PSITTACOTHERIUM ASPASKE CopC. PaleoDtological Bulletin No. 34, p. 192, Feb. 20, 1682; Proceed. Amer. Philos. Soc. 1881, p. li*2. Plato XXIV c, figs. 3-4. Represented by two mandibular rami of two individuals, one adult, the other nearly .so, but with the last inferior molar not fully ))rotruded. The latter specimen must be used for description, as it presents two molar teeth, while the other specimen has lost them. The most obvious difference from the P. mHltifrayum is its inferior size^ INSECTIVORA. 197 which can be readily perceived from the measurements given. The poste- rior crest of the molars appears to have less transverse extent than in the larger species. This crest in the last inferior molar has a curved crenate edge, with a small conic tubercle at its external extremitj-. The anterior crest consists of two conic tubercles, whose apices converge, but whose bases are closely appressed, and only distinguished by a superficial fissure. The valley between the crests is iminterrupted. The preceding molar is larger, and its posterior crest is like that of the lost molar. The apex of the anterior crest is broken off. The ramus deepens rapidly forwards, and contains the enormous alve- olus for the incisors. The coronoid process leaves the alveolar boi'der at the line separating the last two molars, or, in the smaller specimen, a little an- terior to this point, and is quite prominent. The masseteric fossa is well marked, but shallows gradually anteriorly and inferiorly. Measurements, No. 1. u. Depth of ramus at penultimate molar 027 Width of last molar anteriorly 008 Length of crown of do 009 No. 2. Depth of ramus of penultimate molar 029 Dei)th of ramus at P-m. ii 043 Length of five consecutive alveoli 047 From the Puerco bed of N. W. New Mexico. Discovered by my as- sistant, Mr. D. Baldwin. INSECTIVORA. To this suborder I refer the genus Esfhont/x, on account of the near resemblance of such parts of the dentition as are known, to some of the genera now existing. It is not unlikely that other genera of the Eocene which have been referred to the Insectivora belong here. Esthonyx exhibits an approximation to the Tillodonta in the restriction of the enamel-layers of the incisors of one of the jaws to the anterior face only. The inferior molars have much the constitution of those of Anchippodus, and in their details resemble also those of Erinaceus. As compared with the Creodonta, there is a near resemblance between these teeth and the tubercular molars 198 THE WASATCH A>T> BRIDGER FAUN^. of Didy'mictis, and throu 1 :■: < anferoposterior ' Oi*(i Diainetors crown F-'ni. in •; ' I transverse .007 T.. . T> • < anteroposterior 007 Dinmeters crown P-ni. iv •; ' ( transverse Oil Tx- » If • $ anteroposterior OOS Diaiueter.s crown M. i ^ ' i transverse Oil DiameterecrownM.iiiJ»"'*^^°P"«t'^"'"' ^ I transverse 008 Lcnjjih of mandible from incisive border to edge of angle 1-22 Length from incisive border to anterior basis of coronoid process 074 Length of base of coronoid ]iroccss 033 L(;ngth of syrai>hysis (oblique) 043 Depth at P-ni. iii , 0J3 Depth at M. iii 0->3 Depth at condyle 037 Width between inferior canines at base 007 Diameter of base of inferior canine (long) 010 Length of nndar series from canine 053 Length of premolar series OM Diameters crown P-m. ni ^ ""teroposterior (oblique) 0075 ( transverse (oliliipie) ■ — .iXHi Diameters crown P-m. j,- ^ '""•'■'"P"''*''""'- "/" ( transverse 007 DiametersM.i J »""""1""" '■""■• "" ( transverse The internal roots of the superior molars are jn-oduced inwards, giving the crowns a strong internal support and extension at the base. The enamel IXSECTIVORA. 201 is best developed on the internal side, while on the inferior molars it extends further on the external side. A portion of the frontal bone preserved shows that the interorbital reg-ion is flat, and that there is a strono: sasfittal crest. The chambers for the large olfactory lobes fall below the anterior part of the sagittal crest. The glenoid cavity of the squamosal bone is wide anteroposteriorly,and has no anterior crest. The postglenoid foi'amen is rather large. The anteor- bital foramen issues above the j^osteiior part of the third superior premolar. The proximal end of the humerus displays a well-developed, rather flat, greater tuberosity (with a distinct teres facet), which is continued as a prominent bicipital ci'est to the lower part of the shaft. The distal extremity exhibits an epitrochlear foramen. A part of the shaft of the ulna is vei'y robust; both sides are grooved. The shaft of the tibia is quite slender, with the long diameter anteroposterior, the posterior edge acute on the inferior tliird. The edge turns outwards, forming the posterior edge of the wide tibular face. Internal malleolus pi'ominent distally, most so posteriorl3^ The astragalar face is oblique and nearly flat, or slightly concave, having even less excavation than that of most creodonta. Measvrements of limbs. M. Least diameters of humerus ^■'"^'■"^I'°«t'^"»'• 009 < transverse ; 014 De|itli shaft of ulua at middle 012 Diameters shaft tibia ^'^"**'"l«'«t«'"'"- O'^g ( transverse 006 „. ^ » t ii ■ ^anteroposterior OH Diameters extremity tibia •' ' < transverse 015 Tliis species was robust in its characters, and evidently lived on hard food; its strong and worn canines show that they had more than the usual use. In its dentition it stands nearer the creodonta than does any other member of the group. It was probably a burro wer. CONOEYCTES CRASSICUSPIS Cope. Plate XXIII d; fig. 6. The posterior part of a mandibular ramus supporting the last two molar teeth indicates a second and larger species of the genus The ramus is one-half deeper than that of the C. comma, and the second true molar is 202 THE WASATrn and p.ridger fauna. much larger than in that species. Tlie last true molar is much smaller than the penultimate, and consists ot three anterior cusps and a longer heel. The former are obtuse, the external the larger, the internal equal, the ante- rior on the inner edge of the crown. The heel sustains a low conic tubercle. Measurements will be given in the explanation of the figure above cited. From the Puerco beds of northwestern New Me.xico. ESTHOXVX Cope. Report Vert. Foss. New Mexico, U. S. Geoj;. Survs. W. of 100th Meridi.nn, 1874, p. G: Id., Ami. Report U. S. Geog. Survs. W. of 100th Mcridi:iii, 1^74, p. 11;^; System. Cat. Vert. Eocene, New Mexico, U. S. Geog. Survs. W. of 100th Meridi.aii, 1875, p. 23; Report U. S. Geog. Survs. W. of 100th Meridian, vol. iv, pt. ii, 1877, p. l.")3. The dental formula is, I. ^; C. : P-m. ' ; M. -. 6 1 6 6 Incisors of two forms, the inferior subgliriform, but not growing from persistent pulps; the enamel covering a long and narrow external vertical face, and terminating above the alveolus, thus distinguishing crown and root. The superior incisors with the apex incased in enamel, which extends much farther on the outer than the inner side; the crown compressed, not wider than the root. The first superior incisor is large, and the crown is somewhat spoon-shaped. The second incisor is as robust as the first, but the crown is shorter. TJie second premolar has one external and one inter- nal lobe, in the third (fourth) premolar these lobes are much enlarged, and the tooth is transverse. The true molars have two external cusps, which •are flattened, close together, and well within the margin of the base of tlie crown. There is one internal lobe at the junction of two ridges, which in- close a triangular area with the connected bases of the external two cusps; and a strong posterior ledge, as in the opossums. Of the inferior incisors, the median is large and half gliriforni, while the first and third are small. The inferior, like the superior canines, are large. The first and second (third) premolars have no internal lobes, but the second (third) has a heel. The fourth is more or less like the first true molar. The inferior molars support two V's, witli rounded apices directed out- ward, the posterior soon wearing into a triangle lower than the anterior. The anterior is elevated and transverse, only distinguished from a triangle by INSECTIVOEA. 203 a notch on the inner side. Last lower molar with this anterior ti-ansverse triangle, a diagonal ridge, and a heel with raised border. The fourth premo- lar has a V-shaped crest on its anterior half, the angle being an elevated apex of the external face, the limbs descending inward. This genus diffei's from AncMppodus and Ectoganus in the far less gliri- form character of the incisor teeth, although the composition of the molar teeth exhibits a true resemblance to that seen in those genera. The incisor is annectant to the form usual in Mammals, betraying the rodent character in the absence of enamel from the posterior face, and the oblique bevel posteriorly from the apex to the shank. The ? canine or superior incisor (second form) is elongate, and without distinction between crown and root, but is straight, and not gliriform. A resemblance to the superior incisor of Ectoganus can be observed in the deep emargination of the enamel to near the apex on the inner side, and the convexity of the opposite side. A strong resemblance can be discovered between some characters of this genus and Totnitlierium, which is described under the Mesodonta. The composition of the inferior molars in the latter is essentially the same in the two genera, but the anterior cusps and yokes are relatively less developed in Tomitherium. An obvious resemblance is seen in the last premolar, which is somewhat sectorial in the form of its anterior half in both genera. There is no enlarged external incisor in Tomitherium, but either arrange- ment is consistent with mesodont aflfinities, and even incisors of rodent-like character, in view of the structure of Chiromys. Its resemblances to Eri- naceiis are, however, so many that I leave it in the neighborhood of that genus. The premolars of the superior series are nearly alike in the two genera, and so are the inferior molars, excepting the last, which is much smaller in Erinaceus. The superior molars of the hedge-hogs only differ in the development of the posterior cingulum into a posterior internal cusp, which is connected with the posterior external cusp by a transverse ridge. It is probable that this genus represents the group ancestral to the existing Erinaceidoe. 204 EOCENE FAUN^. The following points may be derived from parts of a skeleton of E. hurmeisteri. The i)rocessus dentatus of the axis is short and obtuse, and has an oval section. The doi-sal vertebrae are much smaller than the cer- vicals, and the tubercular articulation is on a long diapophysis. The cau- dals are very large. The scapula has a prominent coracoid hook. The manus has five digits. The scaphoid is larger than the cuneiform, and is di.stinct from the lunar. The trapezium is large and distinct; unciform large. The phalanges are like those of Creodonta. The ilium has a narrow plate with strong external ridge, which makes the section of its peduncle an equilateral triangle. There is a large anterior inferior spine. The distinctness of the scaphoid and lunar bones and the five digits of the manus show that this genus cannot be referred to the family of the JErinaceidce, but to belong rather near to Solenod&n, and perhaps within the boundarie.s of the Centetklce. The specimens show that my original determinations of the incisors based oh loose teeth were correct. They also show that this genus is not far removed from the Creodonta. There are several species of the genus, wliich I define as follows: I. Fourtli inferior premolar like first true molar. Larj;;er; third .superior piemolai* larger; fourth i)remolar with the external cuspbilob- ate E. acutidens. Jledium; third sni)erior i)remi)lar .smaller; fourth premolar with external cusp .simple; .sui)erior incisors wide; large inferior narrower E. burmeisteri. Medium; superior iiK.-isors narrow; large inferior wider U. bisulcatus. II. Fourth inferior premolar with anterior V open and cutting. Smallest; incisors unknown E. acer. A species of the size of E. acer has been named E. S2)atidariKS, but I cannot place it in the above key, as the premolar and incisor teeth are un- known. The section II approximates nearer the genus Conorydes than sec- tion I. ESTHONYX BURMEISTKRI Cope. Report Vertebrate Fos3., New Mexico, 1874, p. 7: Report U. S. G. G. Surv. W. of lOOtli Mer., G. M. Wheeler, iv, ii, p. 156, pi. xi, fig. 26. Plate XXIV6, figs. 1-10. A fractured cranium exhibits the entire dentition ot this species, and gives the characters satisfactorily. The anterior premolars are wanting. INSECTIVORA. 205 The third premolar consists of an external strongly compressed lobe and an internal keel or wide cingulum. The posterior third of the exter- nal lobe is reflected outwards, inclosing a groove Avith the anterior part. The latter rises into an apex, which is separated by an open notch from the posterior portion. The latter has a superior convex edge, and both lobes together present a convex face inwards. The internal lobe is low and sends a ledge continuous with its apex along the posterior base of the crown. Its prominence inwards gives the base of the crown a triangular outline. The fourth premolar is generally similar to the true molars in its trans- versely elongate form, and the production outwards of the anterior external base of the crown as well as the posterior external angle. It differs from them in that the principal external cusp is single and not double, and in the absence of a well-defined posterior internal ledge. On this account the internal angle is more nearly median than in the true molars. There are rudimental antei'ior and posterior cingula on the inner part of the crown. The principal cusp is compressed and acute, and stands well within the ear- like external expansions of the base of the crown. In the true molars there is a rudimental anterior cingulum. The principal cusps are compressed and well separated, though connected at their bases ; those of the first not more so than those of the second, contrary to Avhat is seen in E. acutidens. The posterior external ear-like lobe is a little longer than the anterior in the first molar; a little smaller in the second, and much smaller in the third. Enamel smooth. The inferior molars do not differ much from the corresponding teeth of E. bisidcatus. The anterior limb of the anterior V is not so elevated as the posterior limb, but more so than the posterior V. On the last molar the intermediate lobes are well developed, but the external is much the larger. The anterior V of the fourth premolar has not as great transverse extent as the anterior V of the true molars, but it is well developed, and not a cutting lobe, as in E. acer. The third premolar has an anterior cutting lobe and a posterior keel with a cutting edge continuous with that of the principal lobe. The anterior edge of the latter is convex and rises to the acute apex. The second (first) premolar is two-rooted ; crown lost on both rami. The inferior canine has a robust base, and issues close to the first premolar. Crown broken^ 206 EOCEXE FAUNiE. oflf. The third incisor is a small tooth with small truncate crown, and enamel on the external face only. The second incisor is compressed, and has an elongate crown with the anterior face convex in both directions. The posterior edge is beveled like that of a rodent, but has a thin investiture of enamel, which is worn away by use on a low median ridge. The sides of the crown are covered with enamel. The external side is regularly convex; the inner one is flattened. The first incisor is much smaller than the second, and the sec- tion of the crown is sub round, and narrowed to an angle posteriorly. It is as long as the second incisor, and therefore much longer than the third. The symphysis is coossified and is nearly horizontal in its direction, its plane making an acute angle with the alveolar line. As a consequence the incisor teeth are directed forwards at the base, curving slightly upwards at their summits. Measurements. u. Length of posterior five molars 047 Length of true molars 026 Diameters p.-m. in 5 anteroposterior OOd ( trausverso OOd Diameters p. m. iv 5 anteroposterior 008 ( transverse 010 Diameters m.-ii S anteroposterior 009 < transverse 013 Length of inferior dental series (axial) 074 Length of inferior true molars 028 Length of inferior premolars 021 Diameter of base of canine 007 Length exposed anterior face m. ii 0115 Width posterior face I. ii 0035 Width posterior face I. iii 0020 Diameters p.-m. iii ^anteroposterior 0070 I transverse 0040 Diameters m. ii ^anteroposterior 008 ( transverse 0065 Diameters m. iii ^anteroposterior 0110 ( transverse 0060 Diameters crown superior 1. i \ '""S (oblique) 0080 I short 0055 Length of alveolus of I. ii 0090 Depth of mandibular ramus at m. iii 024 Depth of mandibular ramus at p. m. ii 014 Length of alveolar border of preoiaxillary bone 020 This species is well distinguished from the E. acutidens in the characters of the posterior premolar teeth of the superior series. In the latter, the external lobe of the third superior premolar is much longer, while the inter- nal lobe is smaller than in the E. hurmeisteri. The external lobe of the fourth ' INSECTIVORA. 207 has two lobes instead of one. I mention here that the loose tooth of the E. acutidens, which I figure Plate XXIVa, figs. 17-1 7a, as a first superior premolar, may not really be such, but may be a second superior incisor. From E. Msulcatus, which I discovered in the Wasatch region of New Mexico, this species is separated by the much longer superior incisors and smaller inferior second incisors. Part of the skeleton of a second specimen includes the superior pre- maxillary bone with the second incisor of the right side; parts of the mandible with three incisors and the posterior four molars; vertebrae from various parts of the column; parts of the scapula humerus, manus, pelvis, ribs, and fibula. The generic characters observable in this specimen have been already recited. The atlas is characteristic. The transverse process is on the posterior edge of the vertebra,- and its inferior edge is narrow. It is perforated from before upwards and backwards by the vertebral canal. The lateral canal pierces the neural arch at the middle of its external border. The anterior border of the arch is notched medially. No neural spine. The axis is quite robust and the neural arch is large. The neural spine is elevated and has not an elongate base. The paradiapophysis is small. The inferior me- dian line is keeled. The processus dentatus is constricted at the base above by a groove; its superior face is quaquaversally convex. The posterior articular face is wider than deep, and is oblique. A more posterior cervical centrum has oblique transverse articular faces about as wide as the body is long. The inferior face has a median keel with a concavity on each side. The centra of two dorsals, an anterior and a posterior, are depressed. The inferior median line is a flat band, which widens posteriorly. The two venous foramina of the neural floor are large. The caudal vertebra asso- ciated with the other specimens has no neural arch. It is very lai'ge, more than twice as long as the longest dorsal and one half longer than the axis with odontoid process. It has a ridge on each side, which terminates in a short process posteriorly, and a median ridge below, which terminates behind in a double tuberosity. If this vertebra belongs to this skeleton, the ani- mal had an unusually long tail. 208 EOCENE FAmf^. Measurements of vertebrtB, IL / vertical 018 Diameters of atlas < anteroposterior at side of arch (X*9 ( transverse without diapophysis 021 Uongitudinal J '^"^ <>^'"'«'''l •; ^-^ Diameters of axis < ( without odontoid Olb I-., i-rtical to base neural spine 016 Diameters posterior face centrum axis. J ratis^erse < vertical 007 I anteroposterior 009 Diameters of anterior dorsal centrum. < vertical 0055 ( transverse ("OQ t anteroposterior (K^r, Diameters posterior dorsal centrum. < vertical 006 ' transverse OOSo I anteroposterior 02e5 Diameters caudal centrum. < „„af priori,. 5 vertical 003 ( ■ ' c transverse 0(i9 The glenoid cavity of the scapula is an oval, narrower next the cora- coid, and not produced at that extremity into a tuberosity. In the manus the cubito-carpal articulating surface of the carpus is not very convex in any direction. The proximal surfaces of the scaphoid and lunar bones are concave. The two proximal surfaces of the cuneiform are about equal; that for the pisiform the longer by a little. The scaphoid's greatest diame- ter is transverse. The transverse is the shortest of the lunar. The sizes of the anterior faces of the carpals of the second row are, in diminishing order, the unciform, the trapezium, the trapezoides, and least the magnum. The trapezium is wider than long, and extends distadt over the proximal extremity of the second metacarpal. The proximal extremity of .the second metacarpal is concave; that of the fourth is convex. The fifth has a proximal external tuberosity. Its shaft is proximately as stout as those of the others, which are of subequal proportions, but the second and fifth con- tract more rapidly. Measurements of fore limb. u. Width of extremity of scapula with coracoid 019 Diameters glenoid cavitv '"'*"''I'"«*''"'"" ^}^ l transverse CKnt Anteroposterior diameter humerus below head 013 Width of rarjuis 021 Liutjth of caritus alt trapezoides .008 I anteroposterior 0055 Diameters scaphoid < vertical in front 0045 ( transverse 008^ INSECTIVOEA. 209 M. I anteroposterior 007 Diameters lunar < vertical in front 006 ( transverse 005 I anteroposterior 006 Diameters cuneiform < vertical in front 004 ( transverse 008 c second : 005 Proximal -widths of metacarpals < fourth 005 ( fifth 0055 The ilium is slightly concave longitudinally on the external face. The inner border is abruptly contracted near the origin of the os pubis. The anterior inferior spine is prominent and extended with the length of the ilium; it is four times as long as wide. The groove of the acetabulum is within the anterior margin of the ischium. The posterior edge of the pelvis opposite to the acetabulum is not thinned nor expanded. A bone which may be the radius, or possibly the fibula, has marked peculiarities. The distal poi'tion has for a considerable distance on the inner side a median keel with a gutter on each side. The keel expands into the triangular articular facet. The rest of the shaft has an oval section. The external face of the head has two flat tuberosities, of which the external is much the larger, and has a concave posterior border. This bone is apparently too stout for the fibula and too slender for the radius. As one extremity is lost I cannot be positive as to its position. Its articular face fits the scaphoid and lunar bones. The inner face of the radius in Erinacevs is excavated, but has no keel. Measurements. M. Width of neck of ilium Oil Width of acetabulum 015 Width of neck of ischium 015 Width of (?) distal facet of (?) radius Oil Diameter of shaft of (?) radius near middle 006 The teeth are like those of the specimen first described. The second superior incisor has three sides of the crown ; a large extero-anterior convex, a wider interior, and narrower posterior, plane. The true molars measure .026 on their bases, and the ramus is .023 deep at the anterior part of the last molar. Several fragments of jaws were found by Mr. Wortman, besides the type specimen described, which are probably referable to it. All are from the Big Horn bad-lands of Northern Wyoming. No specimens of the E. acididens have been identified from that region, but several present the measurements of the E. spatularius. 14 210 TOE WASATCn AND BRIDGER FAUN^. ESTHONYX ACUTIDENS Cope. Bulletin U. S. Gcol. Surv. Terrs. F. V. Ilayden, 1681, p. 185. Plate xxiva.figs. 17-21. The largest species of the genus, and represented by two individuals. The first of these includes the last molars of both series and an anterior true- molar ; the second includes most of the dentition of one maxillary bone, the last two true molars being probably the only teeth missing. Four of the molars of this specimen are in ))lace, and three are loose. Under the cir- cumstances, I estimate six molars, of which the foui-th premolar is like the first true molar, and the third premolar has its internal lobe very much reduced. The two preceding premolars have one root, and short, com- pressed, and acute crowns. The second is abruptly very much smaller than the third, and is close to it ; the first is close to the second, and is a little larger. The canine is larger still, and is somewhat compressed. Externally viewed, it looks like the canine of a carnivorous mammal ; but viewed from within, it displays marked peculiarities. It has here a median rib, separated from the fore and aft edges of the crown by a groove on each side. This ridge is without enamel, and the edges are produced and very sharp. The enamel of the external face extends twice as far towards the base as on the interior side. The enamel of this tooth, with that of the premolars, is wrinkled ; that of the molars is smoother. The two external cusps of the last premolar are closer together than those of the true molare. The posterior part of the external basal cingulum of the second and third true molars is more prominent tlian the anterior part. The details of the inferior teeth preserved do not difiFer much from those of the E. bisulcatus, excepting that the heel of the last true molar is much more produced. The E. acididens is considerably larger than either of the species of the genus heretofore described. Measurements. No. 1. M. lertical 00r>5 Diameters of last inferior molar^ antero-postcrior 0130 transverse 0064 ^. . - . , C antoro-po.sferior 0095 Diameters of u I mo molar { . „~., I triinsverse wrii r< ar < tr 0- Vf _..,,, , < anlero-poHtcrinr 0097 Diameters of Jaat buperior iiioliir ? _ _ q.o- MESODONTA. 211 No. 2. M. liengthof five superior molars preserved 0410 Length of premolar series 0325 Length of bases of Pm. I and II 0125 „. . „ „ -., ( antero-posterior 0097 Diameters of Pm. Ill < ^ ' < transverse 0098 T.. . 1. J. i , , c antero-posterior 0086 Diameters of first true molar K „.„,. J transverse 0133 Antero-posterior width of base of crown of canine 0080 Transverse width of base of crown of canine 0050 Wind River Basin, Wyoming. J. L. Wortman. EsTnoNYX sPATULARius Cope. American Naturalist, 1880 (Nov. 25), p. 908. Plate xxiv a, figs. 22-25. Represented by five molar and premolar and two incisor or canine teeth, apparently belonging to one individual. These are about the size of those of E. bisulcatus, but present several differences of detail. Thus the basin of the heel of the last inferior molar is not obliquely cut off by a crest which extends forwards fi-om the heel, but is surrounded by an ele- vated border, which rises into a cusp on the external side. The incisor- canine teeth are more robust than those of E. bisulcatus, one of them espe- cially having a spoon-shaped crown, with the concave side divided by a longitudinal rib, on which the enamel is very thin. The enamel descends much further down on the external than the internal side of these teeth. The rodent-like tooth does not accompany the specimen. Length of base of last inferior molar, .009; width anteriorly, .005; length of crown of canine incisor No. 1, .009; width at base, .005; length of crown of second canine incisor at base, .012 ; width, .006. Basin of the Big Horn River, Wyoming. J. L. Wortman. MESODONTA. Since 1872 the Eocene formations of the Rocky Mountains have been known to contain the remains of numerous species of Mammals which pos- sess greater or less proportions of characteristics of the order Quadrumana. Some of these were referred by their first describers to the Insecfivora, and others to the Ungulata. In October, 1872, the writer described a genus, 212 TUE WASATCH AND BEIDGER FAUN^. Anajitomorphus, represented by a jaw found in the Bridger beds of Wyoming, in wliose dentition Quadrunianous characteristics are so marked as to have induced me to comj)are it with such typical forms as Simia. The characters of the mandibular dentition then recorded are those of the true monkeys, but the permanent separation of the mandibular rami distinguishes the genus from these and from the marmosets, constituting a resemblance to the lemurs. The dental formula is I. 2 ; C. 1 ; P. M. 2 ; M. 3 ; the crowns of the pre- molars with a single, undivided, compressed tubercle. In the following year I published (May 6, 1873) a second paper, in which the characters of Anaptomorphus and of the earlier described TomUherium (Cope) were more fully elaborated. In this essay I refen-ed* the latter genus also to the Quad- rumana, but as expressing a t}'pe even more aberrant than the Lemurs, and therefore well separated from the true monkeys. I cited, as reasons for this reference, the flat ilium, the long femur, the round head of the radius, the form of the distal end of the radius, with the coossified symphysis and four transverse incisors of the lower jaw. I pointed out that the forms of the molars are similar to those of the Quadrumana, and to animals of some other orders as well, while the number of molars is greater than in the Lemurs, or any other known group of the order. The formula of the mandible is I. 2 ; C. 1 ; P. M. 4 ; M. 3. I also pointed out the resem- blance between this genus and Hyopsodus, which was then estimated as Ungulate, but which has since been stated to be Lemurine. Finally, I added to this series, in the same year,t the genus described by Leidy as Nothardus, and a foiirth species, which belongs to tlie genus Pantolestes Cope. In the Actes of the Linna'an Society of Bordeau.x fur 1873, J M. Del- fortrie publislied a description of the cranium of a Mammal which he named Palceolemur betiUei, which he referred to the Lemurs, pointing out certain differences. He gave a number of characters which he deemed sufficient reasons for such a course. Chief among these are the completed orbits, directed partially forwards, which are associated with elongate nasal bones, large petrous bone, and acutely tubercular molars. M. Dclfortric also points •Oil the Primitive Types of tliu Miitiiiiiiili.a Kdiieiiliilia. t Aiiiimil Keport U. S. Gcol. Siirv. Terrs., Itf7-J (pub. 1873), p. 5-19. tAiiii. So. GiSol., t. iv,N(). iv, p. 18, pi. vii, viii, 1874,niMl Jounial de Zoologio, iv, p. 4C-I. MESODONTA. 213 out that the dentition differs from that of the known Lemuridce in the more numerous premolars, giving the following formula: I. ?2; C. 1; P. M. 4; M. 3 ; or the same as that of Tomitherimn. At the time of the discovery of Anaptomoriyhiis, Prof 0. C. Marsh expressed the opinion* that some of the forms noticed by him in the Bridger formation of Wyoming are allied to the Lemurs. He, however, did not state the characters which led him to entertain this opinion, nor did he give such descriptions as would enable the anatomist to judge of its correct- ness. Up to the present date no more complete account of these animals has appeared. The history of discovery of the European forms of this group is simi- lar to that of our own, in respect to the difficulty at first experienced by paleontologists in referring them to their proper systematic position. The investigations conducted by Cuvier during the early part of this century into the extinct Vertebrata of the Eocene of the neighborhood of Paris revealed, among other types, the genus Adapts (Cuv.). This he referred to the Ungulates and to the neighborhood of Anoplotherium. Laurillard and Blainville believed that its affinities were to the Insectivora. The above- mentioned discovery by M. Delfortrie, of Bordeaux, of the greater part of the cranium, at Bebuer (Department of Lot), of his Palceolemur hetilleij-f led him to announce that Lemurs inhabited France during eaidy Tertiary times. This was in confirmation of the opinion of M. Riitimeyer, who had already described a Coenopithecus lemuroides from the Eocene of Switzerland. But MM. Gaudry and Gervais, on further investigation, came to the conclusion that the Palceolemur is the Adapis of Cuvier, and that Aphelotlierium Gerv., and Coenopithecus, are also synonyms of it. And they are disposed to accede to the conclusion of Delfortrie as to its affinities. Subsequently M. Filhol established for this genus, and a new one which he called Necrolemur, a family, the Pachylemuridce, adding a new species, Adapis magnus. In this paper he recognizes the characters pointed out by previous authors as ally- ing this family to the Lemuridce, as well as the higher dental formula which * Amer. Jour. Sci. and Arts, Oct. 8, 1872. t Actes de la Soci(5t6 Liun<5eiiiie de Bordeaux, xxix, 1673. The separate copies of this paper are 'dated May 25, 1873, while a supplement attached to the last page is dated September 4, 1873. 214 THE WASATCH AND BRIDGER FAUNiE. distinguishes it, and adds some important characters which are strongly marked in the genus Adapts. He tinds the cranium to be strongly con- tracted just behind the orbits and at the pterygoid plates, in a manner unknown to existing Lemuridce. Subsequent to the above dates the number of known species of these puzzling Eocene Mammalia has been increasing, and the Wheeler expedition of 1874 added a number of genera and species to those previously known. An illustrated account of these was published in the final report of that organization, Vol. IV. I have seen no reason to modify the view originally expressed as to the Quadrumanous affinities of Anaptomorphus ; on the contrary they have been placed beyond doubt by the discovery of the entire cranium by M. Filhol, of his genus Necrolemur above mentioned, which is very similar to Anaptomorphus, in the parts of both which are known, the mandible and its dentition. Additional light was thrown on the structure of Tomitherium by my researches in New IMexico, conducted in 1874. The fragments of the skeletons of two species of a closely allied genus, Peli/codits, were found, which include numerous bones of the tarsus, and these are identical with corresponding parts in the Creodonta and different from those of the Lemuridce. The astragalus extends anterior to the shortened calcaneum, and the navicular is short and the cuboid not elongate. The superior aspect of the astragalus presents two oblique surfaces, one for the internal malleolus, the other for the transverse facet of the tibia. The portions of femur, including the third trochanter, the proximal part of the ulna, and the distal portion of the humerus, are nil closely similar to those of the Creodonta. The type specimen of Tomitherium includes some parts of the skeleton not present in the New Mexican species. Thus the ilium of T. rostratum, while furnished with the prominent anterior inferior spine of the Creodonta, is flat- tened toward the crest, and is not angnlate on the external face. The femur is furnished with a very elevated third trochanter, which is opposite to the little trochanter, as in Chirnmi/s and Talpa, and not low down, as in Creo- donta. The head of the radius is rounder than in Creodonta. The skeleton of Tomitherium, in fact, bears a strong resemblance to that of ChiromySy leaving the skull out of view. MESODONTA. 215 The skeleton of the New Mexican form includes an entocuneiform, like that of Stypolophus Mans, which indicates a non-opposable hallux. It is apparent that the supposed Lemurine Mammalia of the type of Tomitherium, which have the formula of the molar teeth 4-3, cannot be separated by ordinal distinction from the Creodonta. They differ from them, it is true, in their wholly tubercular molar teeth, but in this relate to them as the Bears and Procyonidoi do to other Carnivora. I have, therefore, pro- posed* to constitute these a distinct group or suborder, intermediate in position between the Creodonta and the Prosimice, under the name of the Mesodonta. I cannot now find characters by which to distinguish this divis- ion from the Insectivora as an order. In my report to Dr. Hayden on the paleontology of the Bridger Eocene of "Wyoming.t I included six species, viz, Tomitherium rostratum, Pantolestes longicaudus, Sarcolemur furcatus, S.pygmceus, Hyopsodus vicarius, and H. pauliis Leidy, which belong to this suborder. As many species of Mesodonta referred to various orders are described by Dr. liCidy in his quarto report in the same series. In my report to Lieutenant Wheeler on the Vertebrata of the Eocene of New Mexico obtained by the expedition of 1874, eleven species are included, none of which had been certainly obtained from the Bridger beds. A synopsis of the genera is given below, in which the characters are derived from the dentition of the lower jaw, the pai-t usually preserved. While considerable variety is to be observed in the structure of the teeth, they furnish also close approximations, so that their discrimination requires careful scrutiny. The genus Anaptomorphus Cope, although included in the synopsis, probably belongs to the Prosimice. I. Last true molar with cusps in opposing pairs. A. Anterior inner cusps, two or a double one, on some of the molars. * Three premolars. "Last premolar without inner tubercle" (Leidy), like the other premolars Omomys. Last premolar with inner tubercle like the molars Microsyops. • * Four premolars ; last molar heeled. Last premolar without inner tubercle; premolars two-rooted.. Pantofes