ELEPHAS (STEGODON). 



37 



which represent the next stage, the transverse ridges are some- 

 what more numerous and at the same time are higher, and the 

 valleys are filled with cement to a greater degree. Nevertheless, 



Vertical longitudinal section of molar tooth of Elephas (Steyodori) insignis. 

 From Lower Pliocene, Siwalik Hills, India. Showing the wide valleys 

 between the cross-ridges filled with cement (a), the dark band marked 

 b being the enamel and beneath that the dentine (c). nat. size. 



these differences are not very marked, and in the case of indi- 

 vidual teeth it is often difficult to be sure to which of these 



Fig. 24. 



Skull. and mandible of Elephas yanesa, showing the immense upper tusks 

 and the shortened chin. From Lower Pliocene, Siwalik Hills, India. 

 About -g-V nat. size. 



species they belong, In some of the Stegodont elephants the 

 tusks attain an enormous size : for instance, in a skull of 

 Etephas (Stegodon] ganesa (fig. 24), exhibited in the gallery 



