TURTLES. 29 



that the feet are flattened into swimming-pad- 

 dles, the toes being united, and enveloped in the 

 same membrane : the anterior pair are greatly 

 lengthened. Only the first two toes are fur- 

 nished with claws, which are pointed ; and one or 

 other of these is apt to fall at a certain period 

 of life. The pieces of which the plastron is 

 composed do not form a continuous plate, but 

 are variously dentelated, and leave wide inter- 



FOREFOOT OF HAVVKSBILL TURTLE. 



vals filled only by cartilage. The ribs are nar- 

 rowed, and separated from each other at their 

 external portion, but the entire circumference 

 of the carapace is occupied by a circle of pieces 

 corresponding to sternal ribs. The plates of the 

 carapace are horny, and for the most part con- 

 tinuous at their edges, as in the majority of 

 other Testudinata, but in some species, as that 

 from which the beautiful Tortoise-shell is ob- 

 tained, the posterior edge of each plate is pro- 

 duced, and overlaps the one that succeeds it. 



The food of the Turtles consists chiefly of 

 various kinds of sea-weeds, such as the Zostera 



