room ir.] natural HISTORY. (Animals.) 49 
pins in bending their head back under the margin of the shell when at 
rest, and cannot withdraw it into the cavity of the shell like the other 
tortoises. These animals will only take their food while in the water, 
when in confinement. 
Case 23. The three-clawed terrapins, which live in the rivers 
of Africa and Asia, and North America; they are strictly carnivorous, 
and eat their food in water; they are to be seen in the Ganges preying 
on the human bodies that float down that river. The lower shelves 
of this Case contain the Marine Turtles, which live principally on fuci, 
sea-weeds, shells, and crustaceous animals : as the Luth of the Mediter¬ 
ranean ; the green turtle, and the imbricated turtle, or tortoise-shell 
turtle of Arabia, which furnishes the best sort of tortoise-shell. 
Cases 24—26. The Crocodiles and Amphisbienas. 
The Crocodiles inhabit both the Old and New World; the alligators, 
only found in America; and the garials, w T hich are peculiar to India. 
The upper shelves of this Case contain the double-headed snakes (A?/i- 
phisboena ), so called because both ends are nearly equally blunt, which 
has led to the idea that they could walk backwards and forwards with 
the same facility. 
Case 26. The Batrachian Animals. 
The lower part of this case contains the toads, frogs, and efts: the 
most remarkable are the tree frogs, which have the power of walk¬ 
ing on polished surfaces, and of attaching themselves by their feet 
to, and walking wdth their bodies suspended on the under side of the 
■smoothest leaves ; they fix themselves directly they alight on any body, 
and, like many reptiles, they have the faculty of changing the colour of 
their skins, which often enables them to elude the vigilance of their 
enemies. The bull frogs of America; the horned toads of Brazil; 
the paradoxical frog from Surinam, the young or tadpole of which, 
when in its fish-like form, is larger than its parent, and has been de¬ 
scribed as a fish; and Pipa of Brazil, which deposits its eggs on the 
back of the male, wdio carries them a certain period, when the young are 
emitted from the cells ; the siren of Carolina, which looks like an eel 
with front legs ; the proteus of the dark subterraneous lakes of Southern 
Europe, which is of a pale pink colour, and blushes when exposed 
to the light; of this there is a very accurate w ax model, to exhibit its 
appearance when alive. 
The Table Cases contain the Sea Eggs, Star Fish, and Encrinites. 
Tables 1— 9. Sea Eggs. 
Tables 1—6. The globular sea eggs. The club-spined echinus 
(Case 3), which has very large club-shaped spines; the tessellated 
echinus, which has short, broad, flat-topped spines like tessellated pave¬ 
ment. The spines easily fall off when the animal is dead, which makes 
specimens with spines on them rare in collections. 
Tables 7, 8. The Sea Pancakes, wdiich are so depressed that there 
scarcely appears to be any room for their internal viscera; some of them 
are lobed or fingered on the margin, and others pierced with slits. 
Table 9. The Galerites, which are most abundant in a fossil state; 
D 
