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Richard Lydekker.

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A few peculiar geckos, assigned to three genera, and of which
Hardwicke's gecko (Eublepkaris hardwickei) is one of the best known
examples, differ from the true geckos in being furnished with movable eyelids, and
also in that their vertebrae are articulated together by means of cup-and-ball joints.
Consequently, those eyelid geckos, as they may be termed, form a distinct family
E nblep haridce.

THE SCALE-FOOTED LIZARDS.
Family PYGOPODIDJJ.

To the ordinary observer it might well appear that the whole of the snake-like
lizards, or those in which the body has become cylindrical and much elongated,
and the limbs either rudimentary or wanting, would pertain to a single family.
Such, however, is not the view of modern zoologists, who regard many of these
abberrarit members of the suborder as having been independently derived from
several groups of fully limbed forms, and thus having but little relationship among
themselves. Of these snake-like groups, one of the most remarkable is that of lite
scale-footed lizards of Australia and New Guinea, which form a family comprising
six genera, all characterised by the retention of more or less well-marked rudiments
of the hind-limbs, although the front pair have quite disappeared externally.
According to the opinion of Mr. Boulenger, the scale-foots come nearest to the
geckos, with which they agree in the essential characters of their skull, as they do
in the nature of their tongue, the want of movable eyelids, and the vertical pupil
of the eye; although the latter character, as being variable in the geckos, cannot
be regarded as of much importance. Apart from their external form, they dili'er
from the geckos and thereby resemble the members of the next family in that the
inner extremities of the collar-bones are not expanded into a loop-shaped form,
while they are peculiar in that the number of bones entering into the composition
of each half of the lower jaw is reduced from six to four. The small and numerous
teeth are closely set, and have generally long, cylindrical shafts, and blunted
summits: although in the genus l/mlis they are sharply pointed, swollen at the 1
Inse, and backward]} 7 curved, thus resembling those of the monitors. The hinder



A GAM DID GROUP.



117



limbs are represented externally by a scaly flap, which is most developed in the
genus to which the figured example belongs; the component bones may be felt
more or less distinctly, and the skeleton of the common species shows five toe-bones.
The common scale-foot (Pygopus lepidopus), which attains a length of about
20 inches, and has a tail twice as long as the head and body, is the typical repre-
sentative of the few members of this family. The head is long, pointed at the
snout, and scarcely separated from the body, being covered above with large
svmmetrical shields, and on the sides with small scales. The ear has an oblique
oval aperture, and the rudimental immovable eyelids are circular and covered with
minute scales. The cylindrical body is slender and of nearly equal thickness
throughout, the scales on its upper surface, as in that of the long tail, being keeled.



\



COMMON SCALE-FOOTED LIZARD ( Hat. S1Z6).




jarger in males than in females, the limbs have rounded extremities, and are
enveloped in overlapping scales. In general colour, this lizard is coppery grey
above, sometimes marked with three or five longitudinal rows of blackish dots or
elongate spots ; the under-parts being marbled grey, with the exception of the
throat, which is white. Found both in Australia and Tasmania, and by no means
uncommon in the warmer northern parts of Victoria, this lizard, like its kin, is
stated to have habits very similar to those of the blind-worm, although accurate
observations on its mode of life are wanting.



THE AGAMOID LIZARDS.
Family AGAMIDJE.

The southern and eastern portions of the Old World are the home of a very
extensive family of lizards, comprising thirty genera and over two hundred



u8 LIZARDS.

species, which may be conveniently termed agamoicls, from the name of the typical
genus. Agreeing with the preceding families in the characters of the tongue, and
in the absence of bony plates beneath the scales, the agamoids resemble the scale-
foots in the characters of their collar-bones ; bat are distinguished from all their
allies in having teeth of the acrodont type, that is to say, situated on the very
summit of the edges of the jaws. While the head is covered with small scales,
the small eyes have circular pupils, and well-developed movable eyelids ; and the
scales on the back are of the normal overlapping type. The thick tongue is either
completely attached or only slightly free in front, and, at most, has but a very
shallow notch in its tip. The teeth may be generally divided into three series,
comparable as regards position with the incisors, tusks, and molars of mammals ;
the latter being more or less compressed, and frequently furnished with three cusps.
while the tusks, which may be one or two in number on each side, are of relatively
large size in most cases, although occasionally absent. The fore-limbs are always
well developed, and, except in one genus, five-toed. The absence of large
symmetrical horny shields, both on the head and under-parts, is a noteworthy
character of these lizards, many of which develop, either in the males or in both
sexes, ornamental appendages, such as crests or pouches. As a rule, the tail is
long and not brittle, but in only one genus is it prehensile, although in another it
can be curled up at the extremity. The shape of the body is very variable in the
different genera, the terrestrial forms being generally depressed, while those that
are arboreal in their habits are compressed. Although the majority of the species
are insectivorous, some subsist on leaves and fruits, while others prefer a mixed
diet; but neither the nature of their habitat nor their food serve to classify the
agamoids, many of the genera of which are very difficult to distinguish. The
majority of the species appear to lay eggs, only the members of a single genus
being reported to give birth to living young. As regards distribution, agamoids
are found from the south of Europe to the Cape, and eastwards as far as China,
the Malayan Islands, Australia, and Oceania, but are unknown in New Zealand and
Madagascar. Both as regards genera and species, their headquarters is, however,
the Oriental region; Africa possessing only three genera, of which one is confined
to the northern part of the continent, while but four species enter South-Eastern
Europe.

Commonly known as flying dragons, the members of the fii
genus of the family are elegant and harmless little creatures
whom such a title seems inappropriate, and we therefore prefer to substitute the
name of flying lizards more especial!}' as we have applied the former appellation
to the extinct pterodactyles. These flying lizards, which are represented by
twenty-one species, ranging over the greater part of the Oriental region, are at
once distinguished from all their kindred by the depressed body being provided
with a large wing -like membranous expansion, supported by the elongated
extremities of the six or seven hinder ribs, and capable of being folded up like
a fan. The throat is furnished with a large membranous expansion, on the sides
of which are a smaller pair ; and the tail is long and whip - like. The best
known of the species is the Malay flying lizard (Draco volans), which is a rather
common form, and belongs to a group characterised by the nostrils being lateral



AGAMOID GROUP. n 9

and directed outwards ; this particular species being distinguished by the absence
of a spine above the eye, by the aperture of the ear being smaller than the eye,
and by the inferior surface of the parachute being ornamented with black spots.
In addition to the appendages on the throat, the males have a small crest on the
nape of the neck ; while in both sexes the back is covered with irregular, large-
keeled scales, and its sides have a series of still larger scales, which are also keeled.
In length it measures a little over 8 inches. As regards coloration, the upper-
parts are of a brilliant but variable metallic hue, ornamented with small dark
spots and wavy cross bands ; between the eyes is a black spot, and a similar
one occurs on the nape ; the parachute is orange, with marblings or irregular
crossbands of black ; and the throat is mottled with black, its appendage being
orange in the male and bluish in the female. This lizard inhabits the Malay
Peninsula, Sumatra, Java, and Borneo ; and in the living state is described as being
so superlatively beautiful as to baffle description.

Essentially arboreal in their habits, the flying lizards generally frequent the
crowns of trees, and as they are comparatively scarce, and seldom descend to
the ground, they are but rarely seen. Describing the habits of the Malayan species,
Cantor says that " as the lizard lies in shade along the trunk of a tree, its colours
at a distance appear like a mixture of brown and grey, and render it scarcely
istinguishable from the bark. There it remains with no signs of life, except the
itless eyes, watching passing insects, which, suddenly expanding its wings, it
seizes with a sometimes considerable, unerring leap. The lizard itself appears to
possess no power of changing its colours." When excited, the appendages on the
throat are expanded or erected ; and the ordinary movements of the creature take
the form of a series of leaps. After commenting on the fact that both flying
j lizards and flying lemurs inhabit the same countries, and have very similar modes
; of life, Moseley states that, when springing from branch to branch and from tree
, to tree, the former pass so rapidly through the air that the expansion of the
: parachute almost escapes notice. Some examples kept on board ship were in
the habit of flying from one leg of a table to another. The females appear to
lay three or four oval whitish eggs.

* Oriental Among a number of genera, characterised by their more or less

Tree-Lizards, compressed bodies and generally arboreal habits, the numerous tree-
lizards constituting the genus Calotes may be selected for brief mention. These
beautiful lizards belong to a group distinguished from many of their allies by the
aperture of the ear being open, while they are especially characterised by the
absence of any distinct fold of skin across the throat, by the equality in size of
the large keeled scales on the back, arid the presence of a large crest on the back
and neck ; the tail being very long and whip-like. One of the best known species
is the variable lizard (G. versicolor), ranging from Baluchistan, India, and Ceylon
to the south of China, an exceedingly handsome lizard of some 16 inches in length,
with a very large crest, but so variable in colour, when alive, as almost to defy
description. It is one of the commonest of the eastern Asiatic lizards, and derives
its name from its power of changing colour, which is especially marked when it
is sitting basking in the sun ; the head and neck being often yellow, flecked with
red, the body red, and the limbs and tail black. When irritated, or feeding rapidly,



,20 LIZARDS.

an allied species (('. <>i>linnn<iclnin\ IVoiii India and Ceylon, turns brilliant red over
the head and neck, the body at the same time becoming pale yellow : hence it
is popularly known as the " blood-sucker."

Ceylon Homed Three remarkable lizards from Ceylon, constituting the genus

Lizards. Ceratopkora, and belonging to a group in which the aperture of the
ear is concealed, derive their name from carrying a more or less elongated horn-
like process on the nose, at least in the male sex; the neck and back being devoid
of a crest. One of the species, which attains a length of about 10 inches, has a
horn measuring half an inch. These lizards appear to be very rare, one of the
species being confined to mountain districts.

For want of a distinct English title, we are compelled to designate
the members of the genus Agama collectively by anglicising their
scientific name. Distinguished from all the previously noticed forms arid their
allies, with the exception of the flying lizards, by their more or less depressed
bodies, agamas are especially characterised by the exposed aperture of the ear, and
the presence of large callous scales in front of the vent in the males. The crest
on the back is, at most, but small, and may be wanting; while each side of the
throat has a pit, and there is likewise a transverse fold across this part. A sac-
like appendage may or may not occur beneath the throat, and the moderately
long tail may be either cylindrical or slightly compressed. Less important
characters are to be found in the form of the head, which is short and triangular,
very broad behind, and rounded at the muzzle, as well as in the relative length
and slenderness of the limbs. The head is covered above with small, smooth scales ;
those on the back are overlapping and keeled ; while on the tail the scales may be
either simply overlapping or arranged in whorls.

The distribution of the genus is somewhat peculiar, impinging on South-Eastem
Europe, and embracing the greater part of South-Eastern Asia, as well as the whole
of Africa, but excluding India proper, together with Ceylon and Burma, although
including the Punjab, Sind, and the Himalaya. As indicated by their depressed
bodies, agamas are mainly ground-lizards, generally frequenting barren localiti
or rocks, although a few species resort to shrubs. The circular pupil of their ey
is equally indicative of diurnal habits ; and a large number of species are fond
basking on rocks in the full glare of the sun. In such situations, as in the valle
around Kashmir, they may be seen in numbers on almost every roadside mass
rock, where their extreme agility renders them very difficult to capture ; the
method, according to the writer's experience, when specimens are required for
preservation, being to strike with the lash of a hunting-whip, whereby they are
instantaneously stunned or killed. As regards food, all appear to be insectivorous.

From among rather more than forty representatives of the genus,
Armed Agama.

three are selected for especial notice. The first of these is the armed

agama (A. armata) of South Africa, which is represented in the figure opposite,
and attains a total length of some 20 inches, of which rather more than 6 un-
occupied by the tail. Belonging to the second great group of the genus, or that in
which the occipital or hindmost median scale on the top of the head is enlarged,
this species is characterised by the spinose scales on the back being of unequal sixe,
by the aperture of the ear being larger than the eye, by the fifth toe being as long




AGAMOID GROUP.



121



.is the first, and the third .slightly longer than the fourth, as well as by the scales
on the abdomen being keeled. Both sexes have a low crest on the nape of the neck,
whereby the species is distinguished from most of its South African congeners ;
while the males have two rows of twelve thickened horny scales in front of the
vent. Although variable, this handsome lizard "is strikingly coloured. Generally
the upper-parts are olive-brown, with the enlarged scales lighter ; and there is a
double series of darker blotches along the back ; the under surface being lighter,




Spinose Agama.



ARMED AGAMA (f nat. size).

and the throat marked with dark longitudinal streaks. Known to the natives of
Mozambique by the name of toque, this species appears to feed chiefly on beetles,
grasshoppers, and ants.

Very different in general appearance to the last species is the
spinose agama (^4. colonorum) of West Africa, which is a rather
large form, and said to be the most common reptile met with on the Gold
Coast. It differs from the preceding species by the shields on the back
being of uniform size and furnished with spines, as well as in the absence of a
crest. The body is not much depressed, and the sides of the head near the ear, as
well as of the neck, are ornamented with radiating groups of short spines, which
are at least equal to two-thirds the diameter of the ear-opening. From an allied
species (A. rueppelli) it may be distinguished by the scales on the back being very
numerous, and considerably larger than those on the tail ; the latter being strongly
keeled and arranged in fairly distinct rings. Attaining a length of rather more



122 LIZAJtDS.

than 13 inches, this species is noticeable for its brilliant coloration in the living
state, although the lines rapidly fade away after death. When alive, the head is
flame-red, the throat spotted with yellow, and the body and limbs a deep steel-blue,
while along the middle of the back there is generally a whitish line. The lower
surface of the basal half of the tail is yellowish, the corresponding upper portion
steely blue, as is the tip, while the remainder is red. Very old specimens have,
however, both surfaces of the base of the tail blue, the remainder of the upper
surface, except a small blue tip, being red. Females are at all ages, much more
soberly coloured. In some spots these agamas are found in swarms, being very
fond of climbing up the mud- walls and mat-roofs of the native huts, at times
basking motionless in the sun, and at others running rapidly about in search of
insects. When approached by a human being, they raise and depress their heads
in a series of nods, which increase in rapidity as the intruder draws near, till,
finally, the creatures lose courage, and disappear, with the speed of lightning,
into some crack or cranny. So brilliant do these gorgeously-coloured lizards
appear, when basking in the midday rays of an African sun, that the observer is
fain to believe he is gazing on some splendid insect rather than a reptile.

Rough-Tailed Belonging to a group of the genus distinguished from the one

Agama. containing the species described above by the absence of enlargement
of the occipital scale of the head, the rough-tailed agama (A. stellio), depicted in the
illustration on p. 105, is interesting as being one of the two members of the genus
whose range extends into South -Eastern Europe. Whereas, however, the other
members of the group have the tail more or less ringed, the rough-tailed agama,
together with the second European species (A. caucasica) and a third (A. microlepis),
are peculiar in that the tail is divided into distinct segments, each composed of a pair
of rings of scales. Growing to nearly a foot in length, the species under con-
sideration is distinguished by its stout body and the moderate degree of depression
of the head ; the cheeks of the male being somewhat swollen. The colour of the
upper-parts is olive, spotted with black, and generally with a series of large yellow
or olive spots down the middle of the back ; the throat of the male having
bluish grey net-like markings. Occurring in Europe, in Turkey, and cer
islands of the ^Egean Sea, the rough-tailed lizard is distributed over the wh
of Asia Minor, Syria, Northern Arabia, and Egypt, being much more common
the latter regions than it is in Europe. To the Arabs it is known by the na
of kardun ; and it is commonly tamed and kept in captivity by the itinen
snake-charmers of Egypt. As shy and agile in its movements as its congene
it feeds largely on flies and butterflies, which are captured with remarkable addiv
and agility.

Before taking leave of this extensive genus, it may be mentioned that there is
a third group, agreeing with the last in the small size of the occipital scale of tin-
head, but distinguished by the absence of rings on the tail ; the agile agama (A.
agilis) of Persia being a well-known example. The genus PhrynocepJm/ //x of
South-Eastern Europe and Central Asia comprises rather more than a dozen lizards
nearly allied to A<J<I ni, but easily distinguished by the concealed aperture of the ear.
Australian Although the swollen callous scales in front of the vent in tin-

Frilled Lizard. 1M;l |,. s ,,f (| H , ;1 gamas have some resemblance to them, the whole of




AGAMOID GROUP. 123

the preceding members of the family are characterised by the absence of true
pores on this part of the body or on the thighs. In a second group such pores
a iv, however, present in both, or in one or other of these situations ; and we select
as our first example thereof the remarkable frilled lizard (Chlamydos<ni ru* kingi)
of Australia the solitary representative of its genus. This extraordinary-looking
creature, which attains a length of nearly 32 inches, about 11 of which are taken
up by the tail, is at once recognised by the curious frill-like membranous expansion
lurrounding the throat and extending upwards to the sides of the nape. The frill,
ich is much more developed in the adult than in the young, has a serrated
rgin, and is covered with scales of larger size than those on the back ; it
sistibly reminds one of the frills with which our ancestors were wont to adorn
ir throats, and communicates an altogether strange appearance to its owner,
form, the body of this lizard is slightly compressed, and although the scales of
back are strongly keeled there is no distinct crest in this region. The aperture
the ear is exposed, and the tail is either round or slightly compressed, the latter
dition occurring in the adult male. The general colour of the upper-parts is
e brown, which may be either uniform or mottled with dark brown, or blackish
ngled with yellow.

The frilled lizard is an inhabitant of Queensland and Northern and North-
estern Australia, as well as some of the islands of Torres Straits ; its fossil remains
urring in the superficial deposits of the first-named district. Recent observa-
>ns show that it inhabits sandy districts, where it walks, with a swinging gait, on
hind-legs, after the manner of the extinct iguanodon. When frightened, it sits
n on its hind-quarters, raises its fore-quarters and head as high as possible,
ikes its body with its tail, and shows its teeth at the intruder. Although the
:ature is perfectly harmless, this attitude has been known to frighten people who
ve seen it for the first time ; and it probably has the same effect on other enemies,
e frill which, when fully extended, forms a shield concealing the body, limbs,
d tail, is moved by certain special muscles, and is supported by rods of cartilage.
sail-Tailed Nearly allied to the preceding is the sail-tailed lizard (Lopkurus

Lizard. amboinensis}, which is likewise the sole member of its genus, and
takes its name from the presence of a tall sail-like crest on the upper surface of
the tail of the adult, which is supported by a great lengthening of the spines of
e vertebrae of that region. The body is markedly compressed, the back has a low
:st, and the throat has both longitudinal puckerings and a transverse fold in the
skin, while the aperture of the ear is exposed. In form, the head is short and
thick, the compressed tail is long and powerful, and the legs and feet are also
strong, the toes of the latter being covered inferiorly with small granular scales,
and at the sides, especially externally, with a fringe of large united scales, which
is one of the distinctive features of the genus. The covering of the upper-parts
is in the form of small quadrangular scales, which are keeled on the head and
back. The dentition comprises six small conical teeth in the front of the jaws,
four long tusks, and thirteen cheek-teeth. On the thighs there is a row of pores.
Attaining a length of over a yard, the sail-tailed lizard is of a general olive-brown
colour, becoming greenish on the head and neck, and spotted and marbled with
black ; while an oblique fold in the skin on the front of the shoulder is deep black.



124



LIZ AX VS.



Originally brought to Europe from Ainboyna, this curious lizard is an
inhabitant of the Philippines, Java, ( lelebes, and tin- Moluccas; it is arboreal in its
habits, and is generally found in wood or scrub in the neighbourhood of water.
Its food consists of seeds, leaves, flowers, and berries, as well as worms, myriapods,
and other creatures found in damp situations. If frightened, this lizard immedi-
ately dives into the water, and endeavours to conceal itself among the stones at




SAii,-TAii.Ki) i.i/Ann (t nat. size).

the bottom, where, however, it may be readily captured with a net, or even with

the hand, as it makes not the slightest attempt at defence. Its eggs are laid in the

sand of the river-banks. By the natives the creature is hunted for the sake of its



Online LibraryRichard LydekkerThe new natural history (Volume 5) → online text (page 14 of 62)