INTRODUCTION. XV11 



shaped. The fresh-water forms are all of them carnivorous ; 

 the neck is therefore long, the legs lax and flexible, and the 

 feet palmated to enable them to pursue their prey with consi- 

 derable rapidity ; whilst the marine Turtles have them modi- 

 fied into true paddles, the toes being entirely concealed by 

 hard scaled skin. These modifications of form are very inter- 

 esting, as evincing an admirable adaptation of a general plan 

 of structure to the varied habits of the different groups. 



The jaws of all these different forms are covered with a 

 hard, sharp, horny beak, the lower portion of which shuts 

 within the upper, and the portions of food are cut or snapped 

 off, as it were, on the principle of shears. The aquatic spe- 

 cies aid the separation of their food, which they seize with 

 their jaws, by tearing it by means of their long and sharp 

 claws. They thus pursue, seize, and tear in pieces living 

 frogs, and other aquatic reptiles, fish, and even young water 

 birds ; and so forcible and violent is their bite, that I have 

 known a stick of half an inch in diameter at once snapped 

 asunder by the jaws of a snapping Turtle, Chelydra serpen- 

 tina ; and a specimen of Trionyx, lately in the possession of 

 Mr. Cross, of the Surrey Zoological Gardens, snapped off the 

 finger of a sailor when on his voyage to this country. 



The whole of the Testudinata are strictly oviparous, and 

 the egg is covered by a calcareous shell, like that of birds ; 

 the eggs of the land Tortoises, as well as those of the marine 

 Turtles, are generally round ; but those of the fresh- water 

 genera are usually more or less oval or elliptical. The multi- 

 tudes of fresh-water Tortoises in some districts is astonish- 

 ingly great, and their eggs form a lucrative article of com- 

 merce from the quantity of oil which is obtained from them. 



It has been already stated that we have no indigenous 

 species of this order. There are, however, on record several 

 well-authenticated instances of marine Turtles, of two distinct 

 species, having found their way to our coasts, one of them 



