190 TUE WASATCn AND IJKIDGER FAUNiE. 



Woitman in the Wasatch Bed-lands of the Big Horn Basin of Northern 

 Wyoming. It has furnished the information necessary to complete our 

 knowledge of the inferior dentition of the genus. It indicates an animal 

 of the size of a tapir, and with a very peculiar physiognomy. This is due 

 to the shortness and depth of face, as indicated by the lower jaws. 



If the anterior border of the coronoid be held vertically, the masticat- 

 ins: surface of the molars is horizontal. The inferior border of the ramus 

 descends steeply to below the second molar, and then rises to the level of 

 the grinding surfaces in a curve which is the arc of a circle. This curve 

 follows the external border of the second incisor, which terminates at the 

 fundus of its alveolus, below the third molar. The ascending inferior bor- 

 der is gently concave below the coronoid process, and passes into the widely 

 convex angle, whose middle is about in the line cff the alveolar edge of the 

 jaw. The condyle is pretty well elevated. Its articular face descends 

 gently inwards, and its convexity looks upwards and a little backwards. 

 The basis of the coronoid is extended anteroposteriorly. The distance from 

 its anterior edge to the posterior border of the ranms is equal to the length 

 from the former point to the anterior edge of the third incisor. The ante- 

 rior edge is thickened inferiorly and extends downwards to below the alve- 

 olar border, and externally to it, and graduates into the surrounding surface. 

 The summit of the coronoid is obtuse. Its posterior border descends to 

 near the condyle, and its superior half is bevelled from an angle of its inner 

 face. The alveolar ridge extends within the base of the coronoid to a point 

 below its apex, and then sinks. Below it the inner face of the ramus is 

 concave continuously with the internal pterygoid fossa. The edge of the 

 angular curve is bevelled on the external side. The angle separating the 

 external face from the bevel is continuous with the posterior margin below 

 the condyle, while the bevelled portion projects beyond it in an angle, half 

 way between the condyle and the inferior border. The latter is not in tiie 

 least incurved. 



The crowns of the first incisors in their present condition display no 

 enamel, and the grinding surface of each is a rather wide oval with the long 

 axis anteroposterior. The second incisor has the usual shoulder or ledge 

 behind the scalpriform portion, as though it could he used for grinding as 



