1388 



CLASS MAMMALIA. 



upper jaw the two transverse ridges unite on the inner border of 

 the crown to form a V ; another V, with its angle directed inwardly, 

 occurring in the corresponding lower teeth. The least specialised 

 genus is Bathyopsis, of the lower part of the Bridger Eocene, in 

 which the lower canine is separated from the incisors, and bites in 

 front of the upper canine in the normal manner ; thus connecting 

 the more specialised forms with Coryphodon. Another form of 

 comparatively small size, distinguished by the absence of nasal 

 prominences, is apparently also entitled to generic distinction, and 

 has been named Elachoceros. The typical forms, according to 



Fig. 1262. — Uintatherium mirabile; from the Bridger Eocene. Reduced. A, Frontal aspect 

 of cranium ; b, Left manus ; c, Left pes. In b the middle bone of the top row is the lunar, 

 while the oval bone on the left of the second row is the trapezoid. The topmost bone in c is 

 the astragalus. (After Marsh.) 



Messrs Scott and Osborn, may all be grouped under the generic 

 name of Uintatherium, although they have been split up by many 

 writers into several genera under the names of Dinoceras, Octotomus, 

 Tinoceras, Eobasileus, and Loxolophodon. This genus may be char- 

 acterised by the presence of nasal tuberosities (fig. 1261), and by 

 the lower canine being approximated to the incisors, which it re- 

 sembles in structure. The dental formula is usually I. -, C. -, 



