Lepidosxeenons. REPTILES. The Chirotes. 85 
under ground, feeds upon earth-worms, slugs, insects, 
&e., and it is said to make especial war upon ants’ nests. 
Family— LEPIDOSTERNID^. 
The second family, that of the Lepidosternons, differ 
chiefly from the true Amphisbsenas, in having their 
chests covered with shields of a larger size and a differ- 
ent shape from those of the rest of the body, and by 
the body having three lines which divide the rings of 
scales into three sets. There are only three species 
described, all natives of Brazil, 
known. This curious-looking animal is about eight or 
ten inches long, and is a native of Mexico. The 
structure of its teeth, and the rings of scales with 
which its body is covered, connect it with the Amphis- 
baenas, otherwise its shape and short legs would lead 
one to place it amongst the lizards, close to the Chal- 
cides. The scales of the body are nearly square, 
and, like the true Amphisbsenas, are divided into two 
sets by a lateral line on each side. The tail is short, 
cylindrical, rounded at the extremity, nearly of the 
same size as the head and body ; and the rings are 
entire, not divided by the line which runs along the 
sides of the body, but which terminates at the vent. 
The number of rings upon the body amounts to one 
Family— CHIROTID^. 
The third family, that of the Chirotes, differ from 
hundred and fifty, and those of the tail to about thirty- 
the two preceding families by the possession of two 
one. The head of the Chirotes is rounded in front. 
legs. These are the front members, and are placed 
and scarcely distinguishable from the body; and the 
near the head. They are, however, very short and 
eyes are almost imperceptible, covered with a trans- 
weak, but are furnished with five toes, four of which 
parent skin, and destitute of eyelids. The feet are 
possess a claw. 
only about four or five lines long, and are covered with 
THE MEXICAN CHIROTES [Chirotes lumhricoides) 
rings of scales similar to those of the body. Little or 
— represented in Plate 3, fig. 4 — is the only species 
nothing is known of its habits. 
Class — AMPHIBIA. — Frogs, Toads, Salamanders, &c. 
The term Amphibia, amphibious animals, is derived 
with persisting gills.” By many naturalists, the Am- 
from the Greek word amphibios [ai^fi^ioi), which 
phibia, instead of forming a class by themselves, con- 
signifies “ having a double life.” The denomination is, 
stitute only an order of the great class. Reptiles. They 
in general language, applied very loosely, to mean any 
differ, however, so much in many essential characters 
animal that is so organized as to resort habitually to. 
from all the other orders of that class, that they are 
and seek its food in the water as well as on land ; to 
fairly entitled to the rank of a distinct class of animals 
any animal, in short, such as the walrus, the otter, 
by themselves. Instead of being covered with scales. 
water rat, &c., whose habits are aquatic as well as ter- 
plates, or shields, the skin is naked, smooth, and often 
restrial. Strictly speaking, however, the term Am- 
moist, and lubricated with a fluid secretion, and aids 
phibious applies only to such animals as have both 
the lungs by affording a surface for the aeration of the 
internal lungs to fit them for breathing atmospheric 
blood. The lungs are equal in size on both sides, and 
air, and gills, such as fishes have, to enable them to 
of a cellular structure ; and the young are subject to a 
breathe in the water. The number of animals so 
metamorphosis. The body of amphibious animals is 
organized, when they have arrived at an adult state. 
either depressed, and squat, as the toad, &c.; elongated. 
is very small; but there are many which at an early 
like the salamanders and newts, &c.; or rounded, as 
stage of their existence are so organized, and at differ- 
the csecilias. The head is depressed and joined to the 
ent periods of their life possess both lungs and gills. 
body without any distinct neck or division. They 
Both of these groups of animals belong to the present 
have all a distinct and well-developed sternum, but the 
class, and the general name of Amphibia has been 
ribs are either only rudimentary or are altogether 
retained by systematic naturalists for them exclusively. 
wanting. The vertebrse or bones of the spine, in the 
In those which at an early age are furnished with 
back, are variable and not easily distinguishable from 
gills, and like fishes, respire water, those organs in due 
each other — in the tailless species, as the frog, being 
time become obliterated, and the lungs then develope. 
only ten, and in the sirens, being ninety in number. 
These are the frogs, toads, newts, &c., and are called 
In many of the species the body is destitute of a tail ; 
Caducibranchiate amphibia, or “ amphibious animals 
while in the others, this organ is well developed. The 
with perishable gills.” In the other group, the gills 
limbs vary in form and number ; in some being well 
ai'e permanent organs, remaining after the owners have 
developed, in others being very incomplete, and in 
acquired lungs, and thus the animal can live indiffer- 
several altogether wanting. The toes are destitute of 
ently either in the water, respiring like fishes, or on 
nails or claws, or, at the most, are only provided with 
land, breathing like mammalia. These are the Axo- 
small horny sheaths. They are in general, however. 
loti, Lepidosiren, Proteus, and Siren, and are called 
well adapted for receiving the impressions of touch. 
Perennibranchiate amphibia, or “amphibious animals 
The sensorial functions are blunt. Though the nerves 
