207 



GENUS MACRORH1NUS. 



THE cranium of the Genus Macrorhinus differs very much from 

 that of other Seals, as do also the teeth, whose formulary is 



The incisors are hooked like the canine, but are much smaller ; 

 the canine are very strong tusks, and the molars have simple 

 fangs, and present this singular appearance that their crowns are 

 smaller than their roots ; they appear like a nipple on the round 

 base which supports them. 



M. de Blainville has given an interesting account of this cra- 

 nium, from which we make a few extracts. " It is a foot and 

 a half long, and the largest we have examined. The sagitto- 

 occipital crest is raised into a sort of pyramid like that of the 

 Rhinoceros. But that in which it differs from all others is its 

 exhibiting a structure capable of sustaining a prolongation from 

 the nostrils. In truth, the forehead is extremely prominent, 

 somewhat like that of the Elephant, and probably for an analo- 

 gous purpose. The nasal bones are very short, and those of the 

 muzzle are longer than in any other kind of Seal, since they form 

 from their anterior extremity to the border of the orbit more than 

 two-fifths of the total length of the head ; and this muzzle is 

 nearly formed entirely of the maxillaries : the space between 

 these bones is entirely hollow, which leaves an enormous nasal 

 opening.* 



* Lib. iupra cit. 



