252 BRANCH CHORDATA 



and scratching, as the snapping turtle; by swimming away or 

 by hiding in the mud, and thus escaping by the protective 

 resemblance. They hibernate in winter in this latitude. 



The leathery shelled sea-turtle (Sphar'gis cariacea) is the largest of all 

 recent turtles. It is from 6 to 8 feet long, and of a dark brown color, and 

 may weigh 500 pounds or more. It is widely distributed in the tropical 

 seas, but it is abundant nowhere. The dorsal and ventral portions of the 

 weak bony shell are continuous. It is buried under a layer of fat which 

 yields " about a pint of oil to each square foot." 1 The sea-turtles have 

 long flat triangular flippers without toes or claws. The front flippers are 

 long. Its flesh is not edible. 



Hard-shelled Sea-turtles (Chdon'idcE) . In this group is found the green 

 turtle, one of the most widely distributed of the Atlantic turtles. It is 

 found from Long Island to Cuba and south to Brazil and also in the 

 Indian Ocean. Its flesh is prized for food. It varies in weight from 50 to 

 500 pounds. 



The tortoise-shell turtle, from which is obtained the valuable tortoise 

 shell, has its upper jaw terminated in a strongly hooked beak. Until the 

 animal is very old the shields overlap one another from before backward. 

 The scales are clear yellowish horn beautifully mottled with black and 

 brown. These turtles do not reach the size of the green turtle; the largest 

 one on record, says Gadow, is 34 inches long. They range over all the 

 tropical and subtropical seas, being found occasionally around the Bahama 

 Islands. 



The soft-shelled turtles (Trionych'idtE) are of wide distribution both in 

 time and space. The shell is very flat and almost circular. It is imper- 

 fectly ossified both above and below, and terminates at the edges in thin 

 plates of leathery skin. When properly cooked the shell is tasty. 2 These 

 turtles are brown, mottled with black above and clear white below, and 

 weigh from 20 to 30 pounds. 



The Snapping Terrapins (Chelyd'ridce). This family includes the alli- 

 gator snapper, the largest North American terrapin of the Gulf States, and 

 our common " snapping turtle " found everywhere in fresh-water ponds 

 and streams. The snapping terrapin has very powerful strongly hooked 

 jaws, a long tail with a crest of bony compressed tubercles, and a small 

 cross-shaped plastron. It seldom leaves the water. It is carnivorous, very 

 voracious, and savage. It is destructive to fishes and water birds. 



The Smooth-shelled Terrapins (Emyd'idce). The diamond-back terra- 

 pin is found (or was until so much hunted for food) in salt marshes from 

 New York to Teaxs. It varies in color from greenish to dark olive or black 

 (rarely). It is small, one weighing a pound is considered large. It is 

 regarded as the choicest variety for a terrapin stew. It is said that there 

 are several " terrapin farms " in the South in which this turtle is being 

 reared for the market. Unless some such provision is made they will soon 

 be exterminated. 



The painted terrapin (Chry'semys pic'ta) is common in most regions east 

 of the Mississippi. The shell is much depressed. The plates of the cara- 

 pace in Chrysemys picta are greenish black edged with yellow, those about 



1 Hornaday, p. 331. 

 1 Ibid. 



