2l8 



SKULL OF ELEPHANT 



Eleplbas alone survives. This genus also includes many extinct 

 forms, both American and European, as well as Asiatic and 

 African. The entirely extinct genera are Stegodon and Mastodcm. 

 The group is clearly one dwindling towards extermination. From 

 the Middle Miocene downwards these great " pachyderms " have 

 existed ; and from the iliocene up to Pleistocene times they were 

 almost world-wide in range and numerous in species. 



The genus Elejjlias comprises usually large, but occasionally 

 (the pygmy Elephant of ilalta) quite small forms. The external 

 features of the genus differ slightly in different species, and will 

 therefore be described in relation to those species which we shall 

 notice here. The vertebral formula is C 7, D 19-20, L 3-5, 

 Sa 4-5, Ca 24-30, or even more. 



The bodies of the vertelirae are remarkable for their shortness 

 and for the very flattened articular surfaces. 



The skull is large and massive. Its large and heavy character 

 is, as has been stated in the definition of the sub-order, due to the 



Fig. 116. — A section of the cranium of a full-grown African Elephant, taken to the left 

 of the middle line, and including the voniei' {Vo) and the mesethnioid [ME) ; «», 

 anterior, and j?;;, posterior narial aperture. x -j^^. (From Flower's Osieo^ot;?/.) 



immense development of air cavities in the diploe ; the diameter 

 of the wall of the skull is actually greater than that of the 

 cranial ca\'ity. These cavities are not obvious in the young 

 animal. They are most conspicuous in the roofing bones of 

 the skull, Ijut are seen elsewhere, and thicken the basis cranii, 



