CHELONIAN REPTILES. 



399 



The Turtles ^Chelonidse] are very remarkable on account of the 

 structure of their limbs. The feet, though the toes are composed of 

 distinct pieces," and armed with sharp claws, are changed into flat 

 depressed fins, only fitted for swimming, an act which they per~ 



FlC. 



. HAVMCSHII.L TUK1LK. 



form with great vigour and celerity. The fore legs are much longer 

 and larger than the hinder ones, and are not retractile within the 

 shell; their carapax is generally heart shaped and exceedingly flat- 

 tened, a form well adapted to admit of rapid movement through the 

 water. 



Turtles feed principally upon marine plants, and only leave the 

 sea to lay their eggs. They swim with great facility, and are some- 

 times met with several hundred miles from land, floating on the 



