264 ECONOMIC ZOOLOGY AND ENTOMOLOGY 



more than 100 pounds. It is largely used for food. Care has 

 to be exercised in handling live specimens for they are of ugly 

 temper and bite severely. 



The painted turtle or painted terrapin, Chrysemys picta, 

 has the carapace beautifully marked and colored. It lives 

 in ponds and sluggish streams, feeding on aquatic plants and 

 any insects or small animals that it may find in the water. 



The famous diamond-back terrapin, M alacoclemmys palustris, 

 lives in the salt marshes along the Atlantic coast. These 

 animals, once very abundant, are now comparatively rare 

 because they have been so much hunted. The price has 

 rapidly risen from a few cents apiece to five or six dollars. 



Still more highly prized for food is the great green turtle, 

 Chelonia mydas. This species is widely distributed in tropical 

 seas and occurs as far north along the Atlantic Coast as the 

 Carolinas. It lives on the roots of eel or turtle grass, and may 

 attain a weight of 500 pounds or more. 



The hawk's-bill turtle or tortoise-shell turtle, Chelonia 

 imbricata, is the source of the beautiful tortoise shell of com- 

 merce. Its shell is made up of a series of shield-like plates. 

 About eight pounds of the valuable dorsal shields are sometimes 

 obtained from a single large turtle of tropical and subtropical 

 oceans. 



The leather-back turtle, Sphargis coriacea, is the largest of 

 the turtles, attaining a length of six to eight feet and a weight 

 of a thousand pounds. It lives in tropical and semi-tropical 

 seas, going on land only to deposit its eggs. Both the fore 

 and hind limbs are modified into broad flippers for swimming. 

 It is not used for food. 



The giant tortoises, genus Testudo, inhabiting some of the 

 tropical islands, often weigh as much as 300 pounds and some 

 of them are estimated to be more than 400 years old. 



Alligators and Crocodiles. The skin of the alligators is 

 thick and tough and covered with horny scales. The legs are 

 well developed, but the animal moves clumsily on land. The 

 long, laterally compressed tail makes them powerful swimmers. 

 There are only two species of alligators, one occurring in China, 

 the other, Alligator mississippiensis, in the southern parts of 



