AQUATIC PACHYDERMATA. 



131 



as the posterior ones become developed, being, indeed, 

 pushed out by their advance. 



The skull of the dugong (Fig. 85) is distinguished 

 by the enormous size of" the intermaxillary bones, «, 

 which extend backwards as far as the middle of the tem- 

 poral fossae, and are bent down with a sudden angle (re- 



87.— Teeth of Dugong, 



minding us of the beak of the flamingo) over the elon- 

 gated symphysis of the lower jaw. In this deflected 

 portion of each intermaxillary bone is lodged the root of 

 a permanent, tusk-like, but not very prominent incisor, 

 there being two of these teeth above, none below. This 

 development and shape of the intermaxillary bones throfvs 



