384 



LAND MAMMALS IN THE WESTERN HEMISPHERE 



form and functions of an incisor and the first premolar those 

 of the canine ; the upper incisors were extremely small and were 

 shed in the adult, just as in the true ruminants. The molars 

 had the selenodont pattern, but the upper molars were 

 very different in shape from those of the joreodonts, resem- 

 bling rather those of the fanthracothere ^Bothriodon (see p. 370). 

 Another difference from the foreodont dentition was that the 



Fig. 206. — ^ Agriochcerus antiquus, White River. Restored from a skeleton in the 

 American Museum of Natural History. 



last lower premolar had acquired the molar form and the last 

 upper one nearly so, a very unusual feature among the artio- 

 dactyls. The skull was almost exactly like that of the White 

 River foreodonts, save in a few details ; the face was somewhat 

 longer, the orbit was open behind and there was no glandular 

 pit on the face in front of the eye. The neck was short and the 

 body long, and the backbone in the region of the loins very 

 stout, the vertebrae of this region having much resemblance to 

 those of the great cats, as though \Agriochoerus were an agile 



