NATURAL HISTORY. • 
ROOM II. ] 
J05 
the occiput is arched and compressed, whilst, in the Senegal species, it 
is flat; some of the species, as the Eared and Hooded Chameleons, 
have the back part of the occiput furnished with two fleshy lobes; 
whilst the Panther and Cape Chameleons have the front of the chin 
furnished with fleshy wattles. Others have the head armed with horns, 
which in some are placed over the eyebrow, as in Brookes’s Chame¬ 
leon ; in others on the tip of the nose, as in the Two-horned Chame¬ 
leon ; in others on the forehead, as in the Three-horned Chameleon. 
The Serpents (Ophidia, Cases 8—19) are without any limbs, or 
have them only in the form of short spurs on the side of the vent. 
Their mouths are capable of being opened very widely, in consequence 
of the bones of the jaw-s being separate from each other, to enable them 
to swallow very large bodies entire. 
The most deadly poisonous serpents ( Venenosa, Case 8) have their 
upper jaws furnished with large, moveable fangs, having a small groove 
on the outer convex edge, for conveying the poison, secreted by a large 
gland placed under the eye, into the wound occasioned by the bite of 
the reptile. The fangs, when at rest, are hid by a fold in the gums, 
and behind them are the rudiments of other fangs, to replace the 
former, if lost. The maxillary bones are small and carry only the 
fangs, but there are two rows of palatine teeth, in the upper part of the 
mouth. They are also generally distinguished by the large size of the 
head, which is only covered with small scales; by the scales of the 
body being usually rough and carinated, and by the tail being very 
short, and, in most instances, thin in comparison with the body. Their 
belly is covered with broad band-like shields. The hinder limbs 
are not developed ; the eyes are placed on the side, and the nostrils on 
the top of the nose. They are arranged in two families. 
The family of Rattle- Snakes ( Crotalid^e, Case 8) have a large pit 
like a second nostril on the cheek, just before the eye. They are di¬ 
vided into several groups according to the structure of the tail, which, in 
the True Rattle-Snakes ( Crotali ), ends in a rattle, formed by a series 
of horny joints, fitting one into the other, which the animal can shake 
at pleasure. There are in the collection several species of this genus, 
and some detached rattles, to shew their structure. The Tisiphone 
( Tisiphone) is much like the Rattle-Snake, but the tail ends in a small 
recurved spine : these are all peculiar to America. The other Snakes 
of this division have the tail simple at the end, and are found both in 
the Old and New World. The Cophias have the head covered with 
scales like those on the back, as the Fer de Lance of the French Ame¬ 
rican Colonists. The Trigonocephali have it covered with large shield¬ 
like plates. 
The next family, that of Vipers, ( Viperidje, Case ,) have the same 
broad head as the Rattle-Snakes, but have no pit before the eyes. 
Amongst these the True Vipers ( Viperce) are distinguished by the 
head being covered w r ith scales like those on the back, and by the nos¬ 
trils being very large. The Nose-horn Viper ( Coluber nasicornis), 
has two horns on the end of the nose ; the male of the Cerastes has a 
long horn-like scale>over each eye, which being absent in the female, 
has caused the latter to be erroneously described as a distinct species; 
the Puff Adder, or Short-tailed Viper ( Vipcra inflata), is the most 
