62 



DINOCERATA. 



A. Cervical vertebras long ; median horn-like processes an- 



terior to the orbit ; nasal tuberosities do not overhang 

 the nasal tips. 



(a) Last molar, with or without a tubercle, occupying 



the- entrance of the valley between the lobes, 

 and but one on posterior basal ridge. Tem- 

 poral fossae not continued beyond the base of 

 the parietal processes. Occipital condyles pro- 

 jecting Uintatherium. 



(b) Last molar never has a tubercle at entrance of 



valley, and has two on posterior basal ridge. 

 Temporal fossae continued very far back ; con- 

 dyles sessile Dinoceras. 



B. Cervical vertebrae short ; median horn-like processes di- 



rectly over the orbit ; nasal tuberosities overhang the 

 entire tips Loxolopliodon. 



Synopsis of species of 



UINTATHERIUM. 



A. With a tubercle occupying the entrance of the valley 



between the lobes of the last upper molar.. U. robustum. 



B. No tubercle at the entrance of the valley. 



(a) Nasals divided by a deep groove ; slender zygo- 



matic arch ; dorsal vertebras compressed. 



U. Leidianuin. 



(b) No nasal groove ; stout zygomatic arch ; dorsal 



vertebrae subcylindrical : . . . . U. princeps. 



UINTATHERIUM. 



Leidy, Proc. Ac. Nat. Sc., 1872, p. 169. Cont. to Ext. Vert. Faun, of Western 

 Territories, p. 93. Cope, Hayden's Survey, 1872, p. 580, etc. 



Skull broader proportionally than in the other genera 

 of the order, ridged and possessing several concavities on 

 the upper surface ; zygomas slender and but little curved ; 

 temporal fossae comparatively short and have well-defined 



