TRIONYX LABIATUS. 
been named, the difference is still more striking. So far from having any 
appearance of carina, the dorsum of Trionyx labiatus is much depressed, its 
height, independent of the rest of the skeleton, not exceeding one sixth of its 
breadth, whereas in carinatus it is not less than a quarter. 
As the specimen was in good health and very active when I received it, I 
hoped that it might have been preserved for a considerable time, and have 
thus enabled me to watch its habits; a circumstance the more desirable, as it 
was the first instance of a Trionyx having been brought alive to this country. 
It died however after I had kept it a few weeks, and I had been unable to get 
it to feed, though it would snap suddenly and violently at the finger or a stick, 
when held within a few inches of the mouth. On being placed in a large 
cistern of water, it instantly sought the bottom, where it usually remained, 
excepting at distant intervals, when it came to the surface to breathe. It was 
evident that its habit was to conceal itself in the mud at the bottom of the 
water; for which its depressed form and the moveable and extended coriaceous 
margin of the body are admirably calculated. A very thin layer of mud was 
thus sufficient to conceal it, and it made its way under it as rapidly, and almost 
in the same manner, as a flounder or a plaice. That such is the ordinary place 
of its habitation is also probable from a fact mentioned to me by Colonel Sykes. 
This gentleman found in the stomachs of several of this genus, which he had 
procured from the Ganges, a large quantity of Uniones, the shells of which 
were broken into small angular fragments, though still covering the animals 
and attached to the mantle. This would appear to indicate that these animals 
live upon food which is to be found stationary, or nearly so, at the bottom of 
the rivers in which they reside, whereas the other groups of the fresh-water 
tortoises pursue their prey, which consists of fish, frogs, and even the young 
of aquatic birds. 
