4O ELEPHANTS. 



this animal the skull, so far as known, does not differ to any 

 great extent from that of Tetrabelodon angustidens. The teeth, 

 however, have advanced considerably in size and complication. 

 The first and second molars may have four or five trans- 

 verse ridges, while in the last there may be as many as six 



Fig. 10. 



Second and third lower molars of (A) Tetrabelodon angustidens and 

 (-B) Tetrabelodon longirostris. nat. size. 



ridges (fig. 16 B). Only one of the milk- molars is now 

 replaced by a premolar, and both this and the other milk- 

 molars are early pushed out by the forward growth of the 

 large molars, only two of which at most on each side remain 



