224 



Description of the Sivatherium, 



[July 



ency without example among ruminants, and exceeding what 'holds in 

 the rhinoceros, tapir, and paheotherium, the only herbivorous animals 

 with this sort of structure. Instead of 'being in nearly parallel slips, 

 they are broad and well arched at their base, and converge rapidly to 

 a sharp tip, which is hooked downwards, over-arching the external 

 nostrils. Along a considerable portion of their length they are uncon- 

 nected with the adjoining bones, their lower margins being free and so 

 wide apart from the maxilla ries, as to leave a gap or sinus of consi- 

 derable length and depth in the bony parietes of the nostrils. The 

 exact extent to which they are free, is unluckily not shown in the 

 fossil, as the anterior margin of the maxillaries is mutilated on both 

 sides, and the connection with the incisiv.es destroyed. But as the nasal 

 bones shoot forward beyond the mutilated edge of the maxillaries, this 

 circumstance, together with their well defined outline and symmetry 

 on both sides of the fossil, and their rapid convergence to a point with 

 some convexity, leaves not a doubt that they were free to a great ex- 

 tent and unconnected with the incisives. 



Now to determine the conditions in the fleshy parts, which the struc- 

 ture in the bony parietes of the nostrils entails. 



The analogies are to be sought for in the ruminantia and pachy- 

 dermata. 



The remarkable saliency of the bones of the nose, in the Sivathe- 

 rium, has no parallel, in known ruminants, to guide us j and the con- 

 nection of the nasals with the incisives, or the reverse, does not imply 

 any important difference in structure in the family. In the Bovine 

 section, the Ox and the Buffalo have the nasals and incisives connect- 

 ed: whereas they are separate in the Yak* and Aurochs. In the 

 Camel, they 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 

 accompanied with very important differences in the form of the corre- 

 sponding soft parts. It is therefore in this family that we are to look 

 for an explanation of what is found in the Sivatherium. 



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

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

 the maxillaries, and incisivesf. In all these animals, the upper lip is 

 highly developed, so as to be prehensile, as in the Rhinoceros, or ex- 

 tended into a trunk, as in the Elephant and Tapir ; the amount of de- 

 velopement being accompanied with corresponding difference in the 

 position and form of the nasal bones. In the Rhinoceros, they are long 



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

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



