REPTILES 241 



Family 5. Cheloniidae. — Marine turtles of large size, in which 

 the shell is covered with large horny plates; carapace depressed, highest 

 in front; head large, covered with plates and incompletely retractile; 

 limbs in form of flippers, with i or 2 claws on each; eggs spherical: 

 7 species, which live in the open ocean in the warmer parts of the 

 earth, coming to the shore on tropical and subtropical beaches to bury 

 their eggs. 



ai Four costal plates on each side. 



bi Plates of carapace imbricated i. Erelmochelys. 



hi Plates of carapace not imbricated 2. Chelonia. 



a2 Five costal plates on each side 3. Caretta. 



1. Eretmochelys Fitzinger. Head broad, with a large median 

 plate surrounded by 7 smaller ones; costal plates 4 on a side; 7 to 10 

 plates on each cheek: 2 species. 



E. imbricata (L.). Tortoise shell turtle; hawk-bill. Body brown or 

 blackish above and yellow beneath; upper jaw with a hooked tip; each 

 foot with 2 claws; length of carapace 750 mm.: tropical seas; the 

 Florida and Gulf coasts; occasionally as far north as Massachusetts; 

 valued for the tortoise shell of commerce, this turtle being the only one 

 which furnishes it. 



2. Chelonia Latreille. Top of head with a large median plate sur- 

 rounded by 7 smaller ones; costal plates 4 on a side; 15 to 20 plates on 

 each cheek; head narrow: 2 species. 



C. mydas (L.). Green turtle. Body olive or brown above, marked 

 with yellow, and yellow beneath; length of carapace 1,200 mm. or less; 

 weight up to 500 lbs.; i claw on each foot: tropical seas; Atlantic 

 Ocean as far north as Massachusetts; valued for food, the fat being 

 green; common. 



3. Caretta Rafinesque. Top of head with a large median plate 

 surrounded by 13 to 20 smaller ones; costal plates 5 on a side; 15 to 20 

 plates on each cheek; head broad: 3 species. 



C. caretta (L.). Loggerhead turtle. Body brown above, yellowish 

 below; feet with 2 claws each; 3 inframarginal scutes; horny ridges on 

 roof of mouth low; length of carapace i m. and more; weight 350 lbs. 

 and more: tropical seas; northward as far as Massachusetts; common on 

 the West India and Florida coasts; flesh and eggs used for food. 



C. kempi (Garman). Bastard turtle. Similar to C. caretta, but 

 with ridges on the roof of mouth high anteriorly and separated by a 

 notch; 4 in framarginal scutes: south Atlantic; as far north as New 

 Jersey. 



