TORTOISES, TUETLES, AND TEEEAPINS. 147 



F.— TORTOISES, TURTLES, AND TERRAPINS. 



Intkodxjotion. — The species of Tortoises which inhabit the territory of the United States 

 and the adjacent seas are forty-two or forty-three in number. With the exception of the Musk 

 Tortoises, all are more or less available for food and other economic uses. The number of species 

 actually in demand, however, is small. It includes tbe Marine Turtles, two- or three species of 

 Soft-shell Turtles, the Snapping Turtle, Ihree or four kinds of Terrapins, and the Gopher or Land 

 Tortoise. Some are too small to be of any great ^alue, and others are of too rare occurrence, at 

 least within the limits of the United States. 



For convenience of treatment, following iu a certain way the classification of Dum^ril,' we 

 may separate the Tortoises into three large groups, namely, (1) the Marine Turtles, (2) the Marsh 

 Tortoises, and (3) the Land Tortoises. 



34. THE MAKINE TURTLES IN GENERAL. 



Mode of life. — The Marine Turtles are especially adapted for their aquatic life. Their bodies, 

 which are large and broad, have a specific gravity almost exactly equivalent to that of the water 

 iu which they are immersed, so that they are able to sustain themselves at the surface of the sea 

 for any length of time without fatigue. Their feet are transformed into broad paddles, enabling 

 them to swim freely and rapidly. The fore-feet are used in propelling the body, while the hind-feet 

 serve as rudders. The motion of the forefeet is very similar to that of a bird's wings, and, indeed, 

 all their movements are more those of flying than of swimming. These Turtles never go on shore 

 except to lay their eggs, and their movements at such times are slow and constrained. 



Distribution op the Marine Turtles. — The Marine Turtles are most abundant in tropical 

 regions, and occur in considerable numbers only along the extreme southern portions of our coast. 

 Specimens are occasionally seen as far north as Long Island Sound, and still more rarely in Massa- 

 chusetts Bay and on the southern coast of Maine. I am further informed by Capt. Joseph W. 

 Collins, a most reliable observer, that he has frequently seen Turtles, which he believed to be Green 

 Turtles, about the fishing banks of Newfoundland. Such occurrences, however, must be considered 

 accidental, and are unimportant from a commercial point of view. 



Species of commercial, importance. — The species which are of commercial impo'rtauce 

 are, 1. The Loggerhead ; 2. TheHawk's-billTurtlesof the east and west coasts; and, 3. The Green 

 Turtles of the east and west coasts. In addition to these, a species known as the "Bastard," 

 Thalassochelys Kempii, Garman, has been recently described. It occurs commonly in the Gulf of 

 Mexico, but is not at all sought for. In contrast to the other species, it lays its eggs in the winter 

 months, from December to February. 



Thk Leather Turtle. — Another species which may be mentioned is the so-called "Leather 

 Turtle," or " Luth," or " Trunk Turtle." It belongs to a different family from those enumerated 

 above, is larger than they, and occurs sparingly all along our Atlantic coast, from Massachusetts 

 Bay to Florida. It has no commercial value with us, so far as known, but in the West Indies a 

 fat is procured from it which is used as a lubricator. 



35. THE LOGGERHEAD TURTLE. 



Distribution op the Loggerhead. — This Turtle is conimouly known in the United States 

 as the " Loggerhead," Thalassochelys caretta, (Linu6) True, in allusion to its large and thick head. 



' Dum:6ril and Bibron : Erp6tologie g^n^rale. 



