8 Lizards. REPTILES. Slender-Tongued Lizards. 
to enter into minute details of these, nor would a dry 
definition of them, according to their zoological charac- ' 
ters, he at all interesting to the general reader. “ The i 
truth is,” says Mr. Griffiths, “ that when we come to 
treat in detail concerning the reptile tribes, there is an 
abundant scantiness of that sort of information con- 
cerning them, which would prove interesting to the 
majority of readers. However useful and curious may 
be the investigation of their specific characters, it must 
be owned to the many it is dry and repulsive. Tt is 
caviare to the general.” We will therefore only select 
a few of the more important or interesting. 
THE MONITORS [Monitor idee) — Monitor, one who 
gives warning or admonishment, from the Latin word 
moneo, to warn or admonish ; these animals being 
believed to give warning of the crocodile’s approach — 
form the first family we shall mention. The Monitors 
are the largest of all the lizard order of reptiles. Their 
body is very long, of a rounded form, and without any 
crest along the back. Their tail, in most of the 
species, is slightly flattened on the sides, and at least 
twice the length of the body. Their feet ai-e strong; 
the toes are five in numlier, very long, but of unequal 
size, and terminate in strong hooked claws. The skin 
on the head, back, and flanks is furnished with small, 
round, tubercular, projecting scales, which are always 
arranged in circular bands or rings. It varies in 
colour from black to a more or less deep green, with 
spots scattered throughout, assuming the form of 
regular patterns, and presenting the appearance of 
beautifully arranged mosaic work. From the firm 
structure of this integument, and the hard ' sym- 
metrical arrangement of the scales, it has been often 
used for covering little trinket cases and other small 
articles, as it is well adapted for resisting the effects 
of friction. They have a long, fleshy tongue, which, 
like that of the serpents, is deeply forked, and is 
capable of being withdrawn into a sheath jdaced at its 
base, and protruded again to a considerable extent. 
Their eyes are large and bright, and the openings of 
their ears are very apparent, and seated low down on 
the skull, near the angles of the mouth. The head is 
covered with small many-sided shields. 
The Monitors are only found in the warmer parts of 
the Old World, none having ever been discovered in 
Europe. They live near the water’s edge, and the 
greater number are aquatic in their habits. A few, 
however, are completely terrestrial, living in dry, 
sandy deserts. Tlie structure of the tail indicates 
their special residentte. lu the aquatic species, this 
organ is compressed laterally, and is surmounted by a 
crest formed of two series of flattened scales. It thus 
becomes a powerful organ of progression, when the 
animals are in the water ; with it they propel them- 
selves along with considerable swiftness, moving it 
from side to side, with powerful and rapid action, and 
steering the body by means of it also, as by a rudder. 
In the terrestrial species, the tail is conical in shape, 
and of a rounded form, appearing as if its only use 
could be to act as a counterpoise to the weight of 
the rest of the body, or, as it rests upon the ground 
it may assist the animals in springing upon their prey. 
Their motion along the surface of the ground is 
rapid but sinuous, like the serpent ; they run swiftly 
' on the level plain, but are not capable of climbing 
i rocks or trees. The Monitors are carnivorous animals ; 
they live upon small quadrupeds, birds, and the larger 
kinds of insects. They often devour the eggs of 
crocodiles and aquatic birds ; and even small fishes, 
lizards, and tortoises fall victims to their voracity. 
M. Dumeril informs us, on the authority of M. 
Leschenault de Latour, that some of the aquatic 
species unite on the borders of rivers and lakes, in 
order to attack quadrupeds coming there to quench 
their thirst ; and that that traveller had seen them 
fasten upon a young deer which was trying to swim 
across a river, pull it under the water, and drown it. 
He had, moreover, found the thigh-bone of a sheep, in 
the stomach of an individual which he was dissecting. 
THE NILOTIC MONITOR [Monitor Niloticus ) — Plate 
1, fig. 1. About twenty-three species of Monitors 
have been described. Of the aquatic species, which 
are by far the most numerous, tlie best known is the 
one just mentioned. The Nilotic Monitor is about 
five or six feet long, and of a greenish-grey colour, 
mottled with black. The nape of the neck presents 
four or five horse-shoe marks of a yellow hue ; and 
along the back seven or eight rows of spots of a 
yellowish-green tint, extend from the shoulders to 
the root of the tail. The tail is compressed through- 
out nearly its whole length, and strongly crested 
or keeled on the upper edge. It is one half longei 
than the body, and is marked on the upper half 
with circular bands composed of spots like those 
on the back, and on the lower moiety with rings of 
greenish-yellow. The legs are strong, and the toes 
are long, and armed with compressed, very sharp, and 
hooked claws. The teeth are short, and consist of 
twenty-two in the lower, and thirty in the upper jaw. 
It is a native of Africa, inhabiting most of the rivers of 
that country. It is very common in the Nile ; and is 
also found in the rivers of North Africa, Western 
Africa, and South Africa, as far as the Cape of Good 
Hope. This animal is held in great veneration by the 
natives of Egypt, who assert that by the hissing noise 
which it produces, it gives warning of the approach of the 
crocodile. Hasselquist informs us that the Egyptians 
have also an idea “ that it is hatched from the eggs of 
the crocodile that have been laid in the sand, whilst the 
crocodile itself is the produce of those eggs which have 
been deposited in the water.” He gravely adds— “ I 
have no need to say that this is false ! ” Representa- 
tions of the Nilotic Monitor occur on the ancient 
monuments of Egypt, and Cuvier has suggested that 
this may have arisen from the belief amongst that 
early people, that they devoured the eggs of the 
crocodile. Its food consists of small animals, insects, 
&c., which it always takes alive. M. Geoffrey St. 
Hilaire says that it is very voracious, and that even in 
captivity, it attacks all the little animals which it can 
reach, and throws itself with the utmost avidity upon 
the food presented to it. When irritated, it whistles 
violently, and tries to bite or strike with its tail. It 
would appear from Sparrmann’s account of an individual 
caught by him at the Cape of Good Hope, that it is 
very tenacious of life. “ One of this species,” he says, 
