TORTOISES AND TURTLES. 391 



be completely retracted within the shell, and the tail is very short. The 

 whole of the hinder region of the skull is covered by a bony roof. There is 

 no bony union between the upper and lower shells ; and in the carapace 

 numerous unossified spaces remain for a long time, if not permanently. 

 Except during the breeding season, when the females resort to shelving 

 sandy shores for the purpose of laying their eggs, turtles are inhabitants of 

 the open sea, where in calm weather they may at times be seen floating 

 placidly on the surface, When on shore, they shuffle along in an awkward 

 manner ; and if turned on their backs are utterly helpless. Their eggs, 

 unlike those of other Chelonians, have soft shells. Like most denizens of the 

 open sea, the three common species of turtles have an almost world-wide 

 distribution. Of these, the green turtle (Chelone my das) is the one whose 

 flesh is used for culinary purposes. Nearly allied is the hawksbill (G. imbricata), 

 distinguished at all ages by the strongly hooked beak, and also by the cir- 

 cumstance that, for a considerable portion of life the horny shields of the 

 shell overlap one another like the slates in a roof, instead of meeting at the 

 edges. It is this species alone that yields the tortoise-shell of commerce. 

 More distinct is the logger- 

 head (Thalassochelys caretta), 

 in which the head is of pro- 

 portionately greater size, and 

 there are five, instead of four, 

 pairs of horny costal shields 

 on the carapace. The logger- 



head is the largest of the three FJG 6 ._ LoGGERHEAD ToRTOJSE 



1 1 is somewhat remarkable that ( i 'halassochelys caretta). 



whereas the green turtle is an 



herbivorous animal, feeding chiefly upon sea-weeds, both the hawksbill and 

 the loggerhead are carnivorous ; the food of the latter consisting largely of 

 cuttle-fish. 



During the egging'- season turtles come ashore in immense numbers, the 

 Seychelles and Bahamas being two of their favourite resorts. While the 

 females are busily engaged in the occupation of laying, and of covering up 

 their eggs in the sand, the males generally pass the time by quarrelling among 

 themselves. Moonlight nights are those usually chosen for resorting to the 

 coast ; and these, of course, are most favourable to the turtle-catchers, whose 

 object is to intercept their victims before they can scuttle back to the sea. 

 Not only are the eggs largely used as an article of food, but they also yield 

 an excellent oil. Tortoise-shell, when heated, has the peculiar property of 

 welding like iron, so that plates of almost any size can be obtained by uniting 

 a number of shields. It can also be pressed into moulds, and beautiful 

 amber-like necklaces and other ornamental articles are manufactured from 

 the scraps and fragments. 



Although the huge leathery turtle (Dermcchelys coriacea) the giant of tho 

 tribe is a marine species with flippers for limbs, yet it differs so markedly 

 from the other turtles in the structure of its shell and tho 

 conformation of its skull, that it unquestionably represents Leathery Turtle, 

 a separate family by itself. Indeed, as regards its shell, not Family- 

 only does the luth (as this species is sometimes called) differ Dermochelyida. 

 from other turtles, but likewise from all other living Chelonia. 

 In place of the carapace being formed by a series of large regularly-shaped 

 bones, some of which are firmly attached to the backbone and ribs, and all 



