AMBLYPODA 



437 



and position to that of the Musk-Deer, descended from each side 

 of the upper jaw. These were present in both sexes, but very 

 much smaller in the female, as Avas also the flange-like process of 

 the lower jaw by which they were guarded. Behind these, and 

 at some distance from them, were on each side above and below 

 six cheek-teeth, of comparatively small size, placed in continuous 

 series, each with a pair of oblique ridges conjoined internally and 

 diverging externally in a V-like manner, and provided with a 

 stout basal cingulum. The normal dental formula was therefore 

 * > c T> P I' m f = 34 ; and the dentition had thus already attained 

 a remarkable degree of specialisation, although the brain was 

 smaller and more rudimentary in characters than in almost any other 



FIG. 190. Skeleton of Uintatherium. mirabile. ^ natural size. (From Marsh, 

 Am. Journ. Set. vol. xii. pi. 2.) 



known mammal. In its comparative length and the absence of a 

 third trochanter the femur of these animals resembles that of the 

 Proboscidea. The first discovered evidences of the existence of 

 animals of this group were described by Leidy in 1872, under the 

 name of Uintatherium (from the Uinta mountains, near which they 

 were found). Subsequently the names Dinoceras, Tinoceras, Loxo- 

 lophodon, etc., have been applied to various members of the group, 

 but the characters by which they are distinguished do not seem of 

 sufficient importance to allow of their separation from the type 

 genus Uintatherium. 1 



Coryphodon. 2 Another interesting form referred to this suborder 

 is Coryphodon, which appears to connect the Uintatheriidce with the 

 most primitive Perissodactyla. It was first described by Owen in 



1 For detailed descriptions and figures of this group, see Marsh, ' ' Monograph 

 of the Dinocerata," Rep. U.S. Geol. Surv. vol. x. (1884). 

 - Owen, Brit. Foss. Mamm. and Birds, p. 299 (1846). 



