268 TlMEHRl. 
are, however, exhibited. Thus of the order Chelonia, 
already described, there are several forms of the various 
tortoises — one the matamata, a species of Chelys^ having 
a very peculiar shield or box. 
Of the order Lacertilia, or lizards, there are specimens 
of the Iguana and the Salempenta. Lizards are distin- 
guished from other reptiles by several charafters. Thus 
they possess small horny scales on the surface of the 
body as in snakes, never bony plates as in the 
crocodiles ; they are provided with two pairs of limbs, 
one or both of which may however be absent, although, 
whatever the condition of the limbs, the internal bones 
(or scapular arch) to which the anterior limbs (if present) 
would be attached, are always present, thus differing from 
the snakes ; the tongue is always free as in snakes, never 
conne6ted throughout to the floor of the mouth as in the 
crocodiles and alligators ; they possess a movable eyelid, 
like the crocodiles, but unlike the snakes ; and the two 
halves of the lower jaw are fused in the front to form a 
solid piece as in the crocodiles, unlike the snakes in which 
the two halves are only connected by ligament. In the 
case containing the spirit specimens already described, is 
to be seen a lizard which is somewhat serpentiform, the 
Chalcis lizard, in which the body is elongated, the four 
limbs extremely small, in fa6l scarcely visible, the an- 
terior limbs with three minute digits, and the hind-limbs 
destitute of toes ; while the so-called " two headed 
snake", which is exhibited in the same case, is completely 
serpentiform, no rudiments of limbs being visible. No 
dangerous or poisonous lizard has been found in Guiana; 
though the bite of several of the lizards, from their 
size, would be very painful and unpleasant. One of the 
