TORTOISES. 



9 



as in other vertebrate animals, are all within, as 

 are also the bones of the pelvis, and even the 

 muscles of the thighs ; so that a Tortoise has been 

 described as an animal turned inside out. The 



SKELETON OF TORTOISE. 



jaws are destitute of teeth, but are invested with 

 horn like those of birds, and form in fact a power- 

 ful beak. The head, neck, tail, and limbs, are 

 clothed with a tough skin, in which are imbedded 

 plates, either connected or detached. 



The sphere of action of the Testudinata is 

 either the land or the water. Of those which are 

 aquatic, some inhabit marshes, pools, and rivers ; 

 others are exclusively marine. The walk of the 

 terrestrial species is slow, even to a proverb ; the 

 legs are short, restricted in motion, and being- 

 placed at a distance from the centre, they form a 

 sort of short crutches, able to drag the unwieldy 



