52 CHELONIAIMBRICATA. 



occasional bars of brown; the neck above is dusky; the chin and throat yellow; 

 the plates of the shell are fawn colour, more or less bright, and marked with radi- 

 ating or waving bars or spots or blotches, varying in size, of beautiful bright 

 chestnut-brown; the sternum is yellow; the extremities and tail are coloured above 

 like the shell, but more dusky, and are dingy yellow below. 



Dimensions. The dimensions of the animal here described were as follows: 

 length of head, 5 inches; length of shell, 18 inches; length of sternum, 11^ 

 inches. 



Habits. In their native condition I am not aware that the habits of this animal 

 differ from those of the Chelonia caretta; they seek the same localities and the 

 same food, but in confinement they seem much more ferocious: I have observed 

 them to bite severely the Chelonia mydas, when swimming together in the same 

 reservoir, though the other gave no offence; nor did he offer retaliation for the 

 injury received. 



Geographical Distribution. The Chelonia imbricata is found only at the 

 extreme southern points of the United States; once only I knew a fine specimen 

 to be driven to the shores of Carolina during an equinoxial storm. 



General Remarks. This animal is only esteemed for the substance it affords 

 called "Tortoise-shell," which is but the lamina or plates that cover the bony 

 shell. Other species of Chelonia have a similar covering, but in no other are these 

 plates sufficiently thick to be of any value in the arts. These lamina arc obtained 

 by exposing the convex portion of the shell to a certain degree of heat, which 

 destroys the connection between the plate and the shell; it is now recurved from 

 the borders toward the centre, and can then be easily removed. These plates 

 vary in thickness and in transparency, and arc consequently arranged in classes 

 of different value. Tortoise-shell is not considered of the best quality unless the 

 animal has reached a certain size, about one hundred and sixty pounds; before 

 that state it is too thin. The quantity obtained varies much in weight in different 



