350 AMERICAN TESTUDINATA. Part II. 



The animal dwells mostly in the water, but comes out from time to time 

 and basks in the sun on the shore, or on any exposed surface, usually in such 

 a position that at the first approach of danger it may drop directly down into 

 the water, or reach it quickly. The slender legs are ill fitted for travelling 

 on dry land, but easily carry the body through the water over its bottom. 

 When surprised away from the water, the animal seeks the nearest hiding-place ; 

 if the danger is close at hand, it quickly withdi'aws the exposed parts into the 

 shield, and, if pressed still farther, it resorts at last to biting, not throwing the 

 head quickly and forcibly out as the Chelydroidte do, but stretching it out rather 

 slowly towards the assailant, and then snapping the jaws forcibly upon it. The 

 manner of withdrawing the legs is very peculiar. The fore legs are carried round 

 before the body ; the elbow, somewhat raised, is carried directly back by the 

 side of the head and neck into the scapular arch, the skin at the same time 

 rolling off towards the feet and shoulders, and leaving its muscles as naked as 

 those of the neck and scapular arch about it ; the foreann is turned back, but 

 not quite on to the humerus ; the hand is either laid in against the head and 

 neck, or turned back on to the humerus. See PI. 4 and 5. The hind legs are 

 withdrawn nearly horizontally, the knees like the elbows, though in a less degree, 

 stripped of the skin ; the foreleg is turned back upon the femur, and the foot 

 again turned forward upon the foreleg. The tail is turned to one side. The 

 head is drawn back to within the scapular arch, the skin rolling off from the 

 neck, Ijut not folding together before the head, as in the Emydoida?. When the 

 plastron is hinged, its ends are raised so that the limbs are pressed still farther 

 up into the carapace. 



The food is pi'incipally animal, but whether exclusively so or not, I do not 

 know. As stated above, the habits of these Turtles are entirely aquatic. Their 

 natural dispositions are a singular mixture of shyness and of fierceness. They 

 remind us of the Insectivora among Mammalia, the rapacious habits of which 

 are also in stranace contrast with their small size and feebleness. Their motions 

 are also quick, though awkward, and almost feverish. When they bite, they 

 strike repeated blows, darting the head only, and not the whole body, as the 

 Chelydroida3 do, — the shoi't tail, and especially the slender limbs, affording no 

 adequate means to throw forward the whole bulk of the animal with sufficient 

 force to aid in the assault. 



The CinosternoidjB lay few eggs only, from three to five, which they deposit 

 on the shore near the water's edge, in holes dug with their hind legs. The 

 eggs have the form of a rather elongated ellipse, with very blunt ends. They 

 have a shining glazed surfoce, much smoother than that of other Turtles. Their 

 shell is very thick and brittle, even more so than in the Trionychidae. 



