ELEPHAS. 



37 



planifrons (figs. 24 & 25), m which the posterior molars may have 

 as many as twelve ridges. This is the last of the elephants in 

 which premolars have been observed ; these teeth are small and 



Fig. 25. 



Vertical longitudinal section of molar tooth of Elephas planifrons, showing 

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

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



closely crowded up beneath the milk-molars, so that when those 

 teeth are greatly worn the premolars are exposed to view, and 

 are no doubt shed as soon as, or even before, the posterior part 

 of the milk-molars they should replace. 



The species E. meridionalis (fig. 26), of which remains are 



Fig. 26. 



Grinding surface of upper molar of Elephas meridionalis. Upper Pliocene, 

 Tuscany. About nat. size. 



found in the Pliocene of Middle and South Europe, seems to be 

 closely related to E. planijrons, and is in about the same stage of 



Pier- 

 case 34. 



Table- 

 case 24. 



