HYRACOIDEA AND PROBOSCIDEA. 



379 



The recent Elephants are exclusively confined to the 

 tropical regions of the Old World, in the forests of which 

 they live in herds. Only two living species are known — 

 the Asiatic Elephant {Elephas Iiidicus) and the African 

 Elephant {E. Africanus). 



Fig. 661. — Skull of the Indian Elephant {Elephas Indicns). i, Tusk-like upper incisors ; 

 m, Lower jaw, with molars, but without incisors ; n, Nostrils, placed at the end of the 

 proboscis. (After Owen.) 



The most important features of the Elephants, from a 

 palseontological point of view, are connected with the nature 

 of the teeth. Canines and lower incisors are invariably 

 wanting, and the " tusks " are formed by an enormous de- 

 velopment of the two upper incisors, which are rootless, and 

 continue to grow throughout the life of the animal. The 

 back-teeth are six in number on each side of each jaw, but 

 owing to their great size and the peculiar mode in which 

 they succeed one another, there is never more than one (or 

 at most portions of two) in place and in use at any given 

 moment. The first three teeth of the grinder-series, which 

 would ordinarily represent premolars, are supposed to be 



