THE BINOTHERIUM. 107 



the general aspect of the skull of the dinotherium^ set- 

 ting aside the tusks of the lower jaw, and its strange 

 alveolar projection, strongly reminds us of that of the 

 lamantin {Manatus, Cuv.). The orbits themselves are 

 very small, but the temporal fossse are very deep and 

 extensive, indicating the great mass of the temporal 

 muscle. The lower jaw is most remarkable. It is armed 

 at the extremity with two enormous tusks (incisors), 

 which, instead of projecting upwards or forwards, sweep 



downwards, and curve gently backwards, having iheir 

 roots imbedded in enormous alveoli. The dentition is as 



0? 0—0 5—5 



follows : — Incisors, - ; canines, -— — : ; molars, r^— r = 22. 



Of the molars the third has three transverse ridges across 

 its surface, the others have two, with the exception of 



