A NEW FOSSIL RUMINANT GENUS. 



the Buffalo have the nasals and incisives connected ; whereas they are 

 separate in the Yak* and Aurochs. In the Camel, tliey are also separate, 

 and this animal has greater mobility in the upper lip than is found in other 

 ruminants. 



In the Pachydermata, both these conditions of structure are present 

 and wanting, in different genera ; and their presence or absence is accom- 

 panied with very important differences in the form of the corresponding 

 soft parts. It is therefore in this family that we are to look for an explana- 

 nation of what is found in the Sivatherium. 



In the Elephant and Mastodon, the Tapir, Rhinoceros and Palseothe- 

 rium there are three pairs of bones to the external nostrils ; the nasals, the 

 maxillaries and incisives. t In all these animals, the upper lip is highly 

 developed, so as to be prehensile as in the Rhinoceros, or extended into a 

 trunk as in the Elephant and Tapir ; the amount of developement being 

 accompanied with corresponding difference in the position and form of the 

 nasal bones. In the Rhinoceros they are long and thick, extending to 

 the point of the muzzle, and of great strength to support the horns of the 

 animal : and the upper lip is broad, thick and very mobile, but little elon- 

 gated. In the Elephant they are very short, and the incisives enormously 

 developed for the insertion of the tusks, and the trunk is of great length. 

 In the Tapir they are short and free except at the base, and projected high 

 above the maxillaries ; and the structure is accompanied by a well deve- 

 loped trunk. In the other pachydermatous genera, there are but two 

 pairs of bones to the external nostrils, the nasals and the incisives : the 

 latter running up so as to join on with the former ; and the nasals, instead 

 of being short and salient, with a sinus laterally between them and the 

 maxillaries, are long and run forward united to the maxillaries, more or 

 less resembling the nearly parallel slips of the Ruminantia. Of this genera 



* CuviER. Ossemens Fossiles, tome iv. p. 131. 

 t CuviER. Ossemens Fossiles, tome iii. p. 29. 

 E 



