108 



CENOZOIC MAMMAL HORIZONS 



UPPER OLIGOCENE— Continued. 



RODENTIA— Continuea 

 Leporid.b. 



Palaeolagus agapetillus Cope 



Palseolagus intermedius Matthew 

 Lepns onnisiamis Cope 



PERISSODACTYLA. 



Hyracodontid.*;. 



Hyracodon sp. div 



Csenopus tridactylus Osborn 



Csenopus platycephalus O. and W 



? Csenopus pacificus Leidy iJ- 



? Caenopus truquianus Cope 



? Caenopus tubifer Cope 



? Caenopus annectens Marsh 



Diceratherium armatum Marsh . . 

 Diceratherium nanum Marsh 



Tapirid.e. 



Protapirus robustus Sinclair 



Protapirus obliquidens W. and E 

 Protapirus validus Hatcher 



Equid^. 



Mesohippus intermedius O. and W. 

 Mesohippus meteulophus Osborn. . 

 Mesohippus brachystj^lus Osborn. . 



Mesohippus acutidens Sinclair 



Mesohippus equiceps (Cope) 



Mesohippus brachylophus (Cope) . . 



Mesohippus longicristis (Cope) 



Miohippus anceps Marsh 



Miohippus annectens Marsh 



Miohippus condoni (Leidy) 



Miohippus validus Osborn 



Miohippus gidleyi Osborn 



Miohippus crassieuspis Osborn 



Anchitherium prsestans Cope 



Ch.\licotheriid^. 



Moropus ("Lophiodon' 

 Moropus senex Marsh . . 

 Moropus distans Marsh 



) oregonensis Leidy 



ARTIODACTYLA. 



Elotheriid.^: (=Entelodontid^). 



Daeodon& shoshonensis Cope 



Boochoerus humerosus Cope 



? Elotherium (=Entelodon) imperator Leidy. 

 ? Elotherium (=Entelodon) calkinsi Sinclair . 

 Elotherium (=Entelodon) cf. ingens Leidy... 

 Elotherium (=Entelodon) ?crassus Marsh... 

 Elotherium ( = Entelodon) bathrodon Marsh. 

 Elotherium (=Entelodon) sp 



a This and the three following species may be referable to Diceratherium. 



b Dxodon Cope, 1878, Boochoerus Cope, 1879, and Dinohyus Peterson, 1906, quite probably refer to 

 one and the same genus, distinguished from Elotherium by slight development of chin bosses, 

 moderate expansion ol dependent processes of jugals, and certain minor changes in the premolars. 

 E. calkinsi Sinclair belongs to this group, and perhaps other John Day species. 



