38 



ELEPHANTS. 



(Stand K),the tusks project for a distance o 9 ft. 9 in. beyond 

 the sockets. 



* In the next stage we pass from the low-crowned Stegodont 

 group to animals in which the ridges are considerably higher 



Fig-. L>5. 



Grinding-surface of an incomplete upper molar of Elephas planifrons. 

 From Lower Pliocene, Siwalik Hills, India. nat. size. 



and the valleys completely filled with cement ; this is called 

 the Loxodont group. The most primitive member is Elephas 

 planifrons (figs. 25 & 26) (Pier-case 34 ; Table-case 24), in which 



Fig. 26. 



Vertical longitudinal section of molar tooth of Elephas planifrons, showing 

 the deeper and narrower valleys completely filled with cement (). The 

 enamel-layer is marked b, the dentine c. nat, size. 



the posterior molars may have as many as twelve ridges. This 

 is the last of the elephants in which premolars have been 



