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NATURAL HISTORY. [UPPER FLOOR. 
The Geckos, ( Geckotidce , Case 4,) are night Lizards, 
having a dull, lurid appearance, with depressed heads, and 
large round eyes. Their body is usually covered with 
small scales, amongst which are frequently larger tubercles; 
and the under side of their toes is generally furnished with 
variously shaped overlapping scales^, or folds of the skin, 
which enable the animal to crawl up glass, and even to run 
with facility, the back downwards, on the ceiling of a room, 
like a fly. They are found in all parts of the world, and are 
divided into many genera, according to the form of their toes. 
The true Geckos have only a single cross series of 
scales, on the under side of each toe. Eublepharis differs 
from the former, by the toes being more slender, and less 
dilated. Pteropleura, which lives in ponds in Java, has 
the skin on the side of the chin, body, limbs and tail ex¬ 
panded into a kind of fin. Many of the species of these 
Lizards, from their lurid appearance, are considered as 
poisonous by the natives of India, and some even assert 
that they infect every substance which they walk over, but 
this is, at least, extremely doubtful; some of them hold so 
fast by their short, sharp, hidden claws as to produce small 
cuts on the skin of the person over whom they walk, 
which in warm climates are painful and difficult to heal. 
Other geckos have the scales under the toes divided by 
a central groove, into which the claws are withdrawn ( The- 
cadactyli). One of these, the Smooth Sheath-claw, ( Gecko 
Icevis ,) has many scales under the toes, and, on being 
caught, the animal, in its exertion to escape, often casts off 
its tail. It does the same if thrown alive into spirits, in 
which case the separated tail contracts, and assumes an 
almost globular shape, and is most usually found in this 
state in collections, whence this species has been generally 
called the Turnip-tail Gecko ( Gecko rapicauda ). The 
Phyllodactyius has only two or three cross scales on 
each side of the claws, so that the ends of the toes very 
nearly resemble the tips of the feet of the common fly. 
In the Ptyodactylus , the scales under the toes spread out 
from a centre, like the sticks of a fan; and the Ur opiates 
from Madagascar, has the scales under the toes very like 
the former, but the edges of its body and tail are spread 
out into fins. 
Another group (. Hemidactylus ) has only the base of the 
