106 



CENOZOIC MAMMAL HORIZONS 



MIDDLE OLIGOCENE— Continued- 



1. 2. 3- 



PERISSODACTYLA— Con, 



TaPIBIO/E, 



Protapirus simplex Wortman and 

 Eaile 



Equid^. 



Mesohippus bairdii Leidy 



Mesohippus obliquidens"^ Osborn 



Mesohippus eulophus Osborn 



Mesohippus exoletus (Cope) 



ARTIODACTYLA. 



Elotheriid^ (=Entelodon- 



TID^). 



Elotherium (=Entelodon) mortoni 

 (Leidy) 



Elotherium (=Ente]odon) ingens 

 Leidy 



Elotherium (==Entelodon) crassus 

 Marsh 



Pelonax ramosus Copea 



DlCOTYLTDiE (=TaGASSUID^) . 



Perchoerus probu.o Leidy 



Perchoerus nanus (Marsh) 



Anthracotheriid^.. 



Anthracotherium curtum (Marsh).. 

 Hyopotamus (=Ancodon) rostra- 

 tus (Scott) 



Leptochcerid^.'' 



Leptochcerus spectabilis Leidy 



Leptochcerus lemurinus (Cope) 



X 



X 



ARTIODACTYLA— Con. 



LEPTOCHCERiD^— continued. 



Leptochcerus robustus (Marsh) . . 



Leptochcerus gracilis Marsh X 



Stibarus obtusilobus Cope 



Stibarus quadricuspis (Hatcher) X 



OREODONTIDiE ( = AGRI0CHCERTDJ<:) . 



Agriochoerus antiquus Leidy X 



Agriochcprus latif rons Leidy X 



Oreodon (=Merycoidodon) culbert 



soni ( Leidy ^ X 



Oreodon (=Merycoidodon) gracilis 



T-eidy X 



Oreodon (=Merycoidodon) colora- 



densis Cope 



Oreodon (=Merycoidodon) pericn- 



lorum Cope 



Oreodon (=Merycoidodon) macro- 



rhinus Douglass 



Oreodon (=Merycoidodon) sp. cf 



bullatus Leidy X 



Leptauchenia sp j X 



1 1 VPERTRAGULIDiE . 



Hypertragulus calcaratus Cope X 



Hypertragulus sp. div X 



Leptomeryx evansi Leidy X 



Eeptomeryx sp. div X 



Hypisodus minimus Cope X 



CAMELIDiE. 



Poebrotherium wilsoni Leidy X 



Poebrotherium labiatum Cooe X 



Poel)rotherium eximium Hay X 



Paraty] opus primajvus Matthew X 



2. 3. 



First phase — Brule, upper part 

 (White River group). 



Protoceras and lower Leptauchenia zones. 



1. Upper Brule, South Dakota and adjoining 



parts of Nebraska and Wyoming. 



2. Lower Martin Canyon, Colorado. 



3. White Buttes, North Dakota.^ 



4. Blacktail Deer Creek, Montana (?).« 



CARNIVORA (FISSIPEDIA). 



Canid^. 



Paradaphaenus cuspigerus (Cope) 



Paradaphaenus transversus W. and M 



Nothocyon geismarianus (Cope) 



Nothocyon lemur (Cope) 



Nothocyon latidens (Cope) 



Cynodictis temnodon W. & M 



Cynodictis oregonensis Merriam 



Mesocyon coryphaeus (Cope) 



Mesocyon Joseph! (Cope) 



UPPER OLIGOCENE. 



Second phase— John Day. 



Diceratherium and Promerycochoerus zones. 



1. John Day, Oregon. c 



2. ? Drummond, Montana. 



1. 



a. 



b. 



c. 





1 



? 





h 





X 



X 





X 



X 





X 







X 







X 



X 





X 



? 



a ? Upper Oligocene. 



b This group may perhaps belong in Dichobunidffi. 



cChiefly auct. J. C. Merriam and W. J. Sinclair. Ihe level of manj' species (marked "? ") is doubtful 

 as it is determined only by character of matrix. Where the level is unknown, it is given as between h 

 and c, the lower beds of the formation being practically barren. 



d Additional species from this region have been described by Douglass since the date of preparation 

 of these lists. See Ann. Carnegie Mus., vol. 4, No. 2, 1907. The Oreodon horizon is also included in 

 these exposures. 



e More probably Lower Miocene. 



