45 
in the Lacertine Siaphos, (S. cequalis), the ears are 
concealed under the skin. 
The Bipes are peculiar for having only two oblong 
lobes in the place of legs. One of the species, the Brazi¬ 
lian Bipes (Pygopus cariococca ), has the tympanum 
hid under the skin, whilst in the New Holland species 
Fraser’s Bipes ( Delma ), the ears are as distinct as in 
the Seines. 
The Blind-worms ( Anguis ) have scales like the 
Seines, but only rudiments of legs concealed beneath 
the skin. 
Cases 6—13 contain the Serpents, animals without 
legs, but with mouths capable of such extraordinary 
dilatation, in consequence of the peculiar mode by which 
the lower jaw is attached to the cranium, that they are 
able to swallow very large bodies, entire. 
Case 6 contains the pre-eminently poisonous serpents, 
whose upper jaws are furnished with large, moveable 
fangs, having a small groove on the convex edge, for 
conveying the poison, (which is secreted by a large 
gland situated under the eye,) into the wound occasion¬ 
ed by the bite of the reptile. The fangs, when unem¬ 
ployed, are concealed by a fold in the gums, and be¬ 
hind them are the rudiments of other fangs, to replace 
the former, if lost. The maxillary bones are small and 
have no teeth but the fangs, but there are two 
rows of palatine teeth, in the upper part of the mouth. 
The poisonous snakes are distinguished by the size of 
the head, which in general is large, and often covered 
with small scales; by the scales of the body being 
usually rough and keeled, and by the tail being very 
short, and, in most instances, thin in comparison with 
the body. 
The most deadly of these have a large pit like a se¬ 
cond nostril on the cheek, just before the eye. These 
have been divided into several groups according to the 
structure of the tail, which, in the True Rattle-Snakes 
( Crotalus ), ends in a rattle, formed by a series of horny 
joints, 
ROOM X. 
Nat. Hist. 
