REPTILIA. 
272 
head and feet, which are particularly large ; their nose is prolonged into a little trunk ; but the most 
strongly marked of their characters consists in having their wndely-cleft mouth not armed with a 
horny beak, as in other Testudinata, but rather resembling that of certain Batrachians, which form 
the genus Pipa. 
The Matamata (T.^?w6na, Gm.).— The carapace bristled with pyramidal eminences, and the body fringed all 
round with laminae, as if cut. An inhabitant of Guiana. 
The Soft Tortoises {Trionyx, Geoff.) — 
Have no scales, but merely a soft skin enveloping both the carapace and plastron, neither of which 
is completely supported by bone, the ribs not reaching to the borders of the carapace, nor being 
united together for more than a portion of their length, the parts analogous to sternal ribs being 
replaced by a simple cartilage, and the sternal pieces being partly dentelated, as in the Turtles, and 
not covering the whole inferior surface. After death it is perceptible, through the dry skin, that the 
surface of the ribs is very jagged. The feet, as in the Emydes, are palmated without being lengthened, 
hut only three of their toes are provided with nails. The horn of their beak is invested with fleshy 
lips outside, and their nose is prolonged into a small trunk. The tail is short, and the orifice of the 
anus beneath its extremity. They inhabit fresh water, and the flexible borders of their envelope 
assist them in swimming. 
The Trionyx of the Nile (T. triunguis, Forsk and Gm. ; T. <egyptiacxis, Geoff.) is sometimes three feet long, and 
of a green colour spotted with white ; the carapace but slightly convex. It devours the young Crocodiles as soon 
as they are excluded, and thus renders more service to the Egyptians than even the Mangouste. 
The American Trionyx {T.ferox, Gm.) inhabits the rivers of Carolina, Georgia, Florida, and Guiana; and lies 
in ambuscade at the roots of the weeds, seizing on birds, reptiles, &c., and (devouring the young Alligators, 
while itself becomes the prey of the larger ones. Its flesh is good eating. There are several more. 
THE SECOND ORDER OF REPTILES,— 
SAURIA,— 
Have the heart composed, as in the Chelomia, of two auricles, and a ventricle sometimes 
divided by imperfect partitions. 
,, Their ribs are moveable, attached partly to the sternum, and can rise and fall for the 
^purpose of respiration. 
Their lung extends more or less towards the hinder part of the body, often penetrates con- 
siderably forward below, and the transverse muscles of the abdomen slide under the ribs so 
far as to entwine the neck. Those in which the lungs are most developed exercise the singular 
faculty of changing the colours of their skin, according as they are influenced by their wants 
or by their passions. 
Their eggs have an envelope more or less indurated; and the young issue from them with l | 
the form which they retain ever afterwards. ; I 
The mouth is always armed with teeth ; their toes, with very few exceptions, are furnished ; | 
with nails ; the skin is covered with scales more or less serrated, or at least with little scaly j !' 
granules ; and they engender with either a single or double male organ, according to the genus, j 
All have a tail more or less lengthened, and in nearly every instance very thick at the base : ! | 
the greater number have four limbs, though some have only two. 1 1 
Linnaeus arranged them into only two genera, the Dragons and the Lizards ; but the latter 1 1 
requires to be divided into several, which differ in the number of feet, of intromittent organs, ! f 
in the form of the tongue, of the tail, and of the scales, so that we are obliged to separate |j 
them even into families. 
The first of these, or that of the Crocodiles, comprises but one genus, — ' 
The Crocodiles {Crocodilus, Brongniart), — ;i 
Animals of large size, which have the tail flattened at its sides, five toes on the fore-limbs, and four on I 1 
