552 



CHELONIDvE, OR TURTLES. 



of the species feed upon marine plants ; but the Hawksbill 

 (Fig. 328), so named from the peculiar hooked form of the end of 

 the upper mandible, also eats Crustacea, Shell-fish, Echini, &c. 

 These animals are found in all the seas of warm climates, but 

 principally in the tropical ocean ; though stragglers occasionally 

 arrive at our own shores. They have their favourite breeding- 

 places, to which thousands periodically resort, often travelling 

 thither from immense distances ; these are usually islands situated 

 in the midst of the open ocean, such as the island of Ascension, 

 which is one of those most frequented by them. At other times 

 they are found at the distance of many hundred leagues from 

 any land. The species most valued as food is the Chelone midas, 

 or Green Turtle; this occasionally attains an enormous size, 



measuring six or seven feet in 

 length, and weighing from five to 

 eight hundred pounds; its ordi- 

 nary bulk, however, is much less. 

 The Chelone imbricata, or Hawks- 

 bill Turtle, is the one most in re- 

 quest for its covering of horny 

 plates, which are known as tor- 

 toise-shell; these plates are of large 

 size, and lie over one another like 

 the tiles of a house, so that each 

 is overlapped by the one in front 

 of it, to one-third of its extent. 



Fro. 328. HAWKSBILL TURTLE. Hence, although this Species is not 



nearly so large as the Green Turtle, the plates are of greater dimen- 

 sions, as well as of finer quality. Its flesh, however, is neither 

 so palatable, nor so wholesome. One other species maybe noticed, 

 the Sphargis, or Leathery Turtle ; which differs from all other 

 Turtles, in having the bones covered with a leathery skin, instead 

 of with plates. When attacked and wounded, it utters loud, 

 piercing cries, which have been heard nearly a mile off. It 

 sometimes attains dimensions as great as those of the Green 

 Turtle. Its flesh appears to be very unwholesome. 



489. Little is as yet known of the fossil forms of this order ; 



