188 OUR REPTILES. 



ridges to which we have alluded strengthened this 

 supposition ; the ancient lyre having, according to 

 some writers, that number of strings. 



The carapace is heart-shaped, the hinder ex- 

 tremity much pointed ; an elevated ridge follows 

 the dorsal line from end to end ; and on either side 

 of this central ridge are three parallel ones, equi- 

 distant from each other; between these ridges the 

 surface is quite smooth ; the head is without plates ; 

 the jaws are very strong ; the lower jaw turns 

 upwards at its extremity, forming a hook, which is 

 received into a corresponding channel in the upper 

 jaw. In the young, the lines on the carapace are 

 formed by a succession of tubercles in rows, and the 

 entire surface, both of it and of the plastron, is 

 warty. The eyelids are divided almost vertically ; 

 the fore feet, or fins, are as long again as the hinder, 

 the latter, however, being the wider ; there is no 

 trace of nails to the toes ; the tail is as long as the 

 point at the hinder extremity of the carapace. The 

 general colour is brown, with numerous pale yellow 

 spots on the upper surface ; the legs and tail are 

 black. 



The entire length sometimes exceeds six feet.* 



* Clermont's " Quadrupeds and Reptiles of Europe," p. 169. 



