CISTUDA CAROLINA. 11 



frequently the eighth, ninth, tenth and eleventh marginal plates, and sometimes 

 the twelfth, are revolute, and form a gutter. 



The sternum is oval, with an entire margin, and consists of two sections, of 

 which the posterior is larger; these sections are joined to the shell and to each 

 other by a ligamento-elastic structure, so that both valves are moveable on the 

 same axis, and can be brought in contact with the carapace, and thus conceal the 

 head, neck, extremities and tail of the animal. The gular plates are triangular, 

 with their bases forwards; the brachial and thoracic are quadrilateral, the former 

 the most regularly so; the abdominal are quadrilateral and large; the femoral and 

 subcaudal plates are triangular, the former with their apices truncate. 



The head is small; the nostrils anterior and closely approximated. The eyes 

 are large; the pupil black, the iris varying from golden to red or gray. The upper 

 jaw has a broad hook, and the lower is furnished with a small one in front. 



The anterior extremities are short, rounded, and covered with large scales in 

 front and smaller behind; there are five fingers, palmated, and each furnished with 

 a short, thick, slightly curved nail. The posterior extremities are rounded above, 

 but flattened at the tarsus, and covered with small scales, having only a few large 

 ones behind; there are five toes, palmated, four only of which are furnished with 

 nails. The tail is very short and thick. 



Colour. In no other tortoise is there such a great variety in the colour and 

 markings of the shell; I have seen more than one hundred living specimens 

 together, and could not select two precisely alike. Perhaps the most ordinary 

 colour of the shell is yellowish-brown, with spots or stripes of bright yellow; 

 sometimes these are subradiating, or even radiating; at others they are disposed 

 without order; occasionally there is an entire vertebral line of bright yellow, but 

 most frequently it is interrupted with black. This arrangement of the colours 

 often gives to the carapace the appearance of tortoise shell. 



