PART I. ZOOLOGY. 
29 
hemispheres, and are eaten by the North Americans and the natives of 
India. Some grow to a large size, as the crocodile or snapping tor- 
toise of America, and the thurgi tortoise of India. On the lower 
shelves of Case 22 are the Chelydce , which differ from the other terra- 
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. 
Case 24. The specimens of Crocodiles. 
The Crocodiles inhabit both the Old and New World ; the alligators, 
only found in America ; and the gavials, which are peculiar to India. 
The lower shelves of this Case contain the double-headed snakes ( Am - 
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. 
Cases 25 — 26. The Batrachian Animals. 
The toads, frogs, and efts : the most remarkable are the tree frogs, 
which have the power of walking on polished surfaces, and of at- 
taching themselves by their feet to, and walking with their bodies sus- 
pended 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 described as a fish ; and Pipa of Brazil, which de- 
posits its eggs on the back of the male, who 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 sub- 
terraneous 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 
wax model, to exhibit its appearance when alive. 
The Table Cases. 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. 
