ROOM X, 
Nat, Hist. 
/ 
$6 
The third kind of fresh-water Tortoises (Trionyx), 
are peculiar from having the shell covered with a 
naked skin, and only three toes of each foot pro¬ 
vided with claws. They, like all the o-ther fresh¬ 
water Tortoises, are strictly carnivorous, and eat their 
food in the water. Many large specimens of this 
genus are found in the East Indies, and are constantly 
seen preying on human bodies as they float down the 
Ganges. There are in this case young specimens 
of two of these species, the Hurum Trionyx (Trionyx 
hurum ), and the Punctated Trionyx (Trionyx puncta- 
his). The latter is peculiar for the leg being covered 
by a moveable flap placed on the sides of the chest 
when drawn up. 
The marine Tortoises or Turtles ( Chelonice ), are 
distinguished by their feet being compressed and fin 
shaped; they live principally on fuci and sea weeds. 
It is this kind of Tortoise which is most commonly 
used as food, and great quantities of one of the species 
( Test. Midas) are brought to this country for that pur¬ 
pose, The horny plates of the Imbricated Turtle 
{Test, imbricata ) afford the best sort of tortoise shell. 
Over the mantel-piece is a large specimen of the Co¬ 
riaceous Turtle, caught on the coast of Dorsetshire. 
The Alligators, which are peculiar to America, are 
distinguished from the Crocodiles, which are found 
both in the old and New World, by their feet having 
the toes free, that is, without webs, and by the canine 
tooth of the lower jaw being received in a pit in that 
jaw, while in the Crocodiles, they are received in a 
notch on its margin. The Gavials agree with the Cro¬ 
codiles in regard to their teeth, but differ by the muzzle 
being very long and slender. Specimens of all the 
three genera are in the Collection. The upper jaw r of 
these animals is generally, but erroneously, said to be 
moveable; the mistake having arisen from the lower jaw 
being much produced posteriorly. 
Case 2 contains those Saurian Reptiles which have 
the 
