ORDER UNGULATA. 



1393 



one, while in the more specialised forms this action has been con- 

 verted into a perfect grinding motion." 1 



The pelvis of the Proboscidea is characterised by the vertical 

 position and great expansion of the large ilia, and the very small 

 size of the ischia and pubes, both of which enter into the formation 

 of the very short symphysis. 



The Proboscidea make their first appearance in the Middle Mio- 

 cene (Sansan stage) of Europe ; but we are still unacquainted with 

 any form which connects them decidedly with the other suborders 

 of the Ungulata, although Dinotherium affords an inkling of how 

 such a transition may have taken place. The Mastodons prob- 

 ably originated in Europe, from whence they travelled to India, 

 and there gave origin to the peculiar Stegodont group of Ele- 

 phants, which are the parents of the existing specialised forms. 

 From the eastern regions of the Old World it seems probable 

 that the higher Elephants travelled back to Europe, while they 

 also reached North America in the Pleistocene epoch ; Mastodons 

 having arrived in the New World during the preceding Pliocene 

 period. 



Family Dinotheriid^e. — This family is at present known solely 

 by the genus Dinotherium, of which the remains are found in the 



Fig. 1266. — Skull, and lateral (a) and oral (b) aspects of the first lower true molar of Dino- 

 therium giganteum ; from the Upper Tertiary of Europe. All the figures are reduced ; the 

 reduction of b being less than that of A. 



Miocene and Pliocene of Europe and India. The type species is 

 D. giganteum (fig. 1266), originally described by Cuvier, upon the 

 evidence of a molar tooth from the Middle Miocene of the Orlean- 

 nais, as a gigantic Tapir, but better known by the cranium and 



1 Quoted from the writer's ' Catalogue of Fossil Mammalia in the British 

 Museum,' pt. iv., from which other extracts have already been made. 



