DINOCERATA, TILLODONTIA, AND TOXODONTIA. 



;7i 



tion, the front of the upper jaw was destitute of incisors, and 

 probably carried a palatine pad, but there were two very large 

 canines in the form of tusks directed perpendicularly down- 



Fig. (556. — Skull of Dinoceras mirabik (after Marsh). From tlie Eocene Tertiary. 



wards ; and there was also a series of six small molars on 

 each side. In the lower jaw are six incisors, small canines, 

 and twelve prtemolars and molars, six on each side. The 

 dental formula is thus — 



0—0 



1 



pvi 



= 34. 



The crowns of the molar teeth exhibit each a pair of 

 oblique ridges, confluent on the inner side of the tooth, but 

 diverging outwardly in a V-like manner. From the very 

 small comparative size of the molars, and the fact that the 

 condyle of the lower jaw is transversely elongated, thus allow- 

 ing only of up-and-down movement, it has been conjectured 

 that the food of Dinoceras must have been of an animal 

 nature. Superiorly each maxillary bone carried a well- 

 developed process, probably of the nature of a horn -core. 

 The nasals support two similar but smaller horn-cores ; and 



