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At the slightest sound, they raise the head, inflate the throat, and elevate the
crest ; and as soon as the bright, yellow-irised eye detects the presence of a foe,
the basilisks throw themselves instantaneously into the water above which they
are usually reposing. In swimming, the head and neck are raised, the fore-limbs
serve the part of propellers, while the crested tail acts as a rudder; hence the
common name of " ferrymen " is applied to these lizards. At the end of April or
beginning of May the female lays from twelve to eighteen eggs in some cranny at
the foot of a tree, where they are left for the sun to hatch.

Ridge-Headed Nearly allied to the basilisks are the three species of ridge-headed

Lizards. lizards (Corytliophanes) of Central America, characterised by the hrad
being prolonged backwards into a bony, helmet-like projection, while the tail is
devoid of a crest, although the neck and back are provided with a low appendage
of this nature. On the throat there is both a pouch and a transverse fold. The
most interesting of the three species is the one named C. kernandezi, in which the
head is crowned with a helmet-like prolongation so like that of the chamseleon that
the creature is commonly spoken of under that name by the Mexicans. Like the
anolis lizards, these reptiles are in the constant habit of changing their somewhat
sombre colours ; and it has been observed in a captive specimen that whereas the
patch on the pouch was white during the day, at night it assumed, like the other
light parts of the body, a blackish hue.

While agreeing with the basilisks in having the plates on the
Stilted Lizards

under surface of the toes distinctly keeled, there are a number or

genera in the family distinguished by the absence of any backward prolongation
of the crown of the head. Among these we select for mention the stilted lizards,
specially characterised by the large size of the occipital shield of the head, the
presence of a vacuity in the breast-bone, the small or moderate-sized scales of the
tail, the long and highly curved toes, and the presence of tusk-like teeth in
the jaws. There are but two representatives of the genus, both of which have
a wide distribution in South America. The figured species (Uraniscodon uml>r<i),
which attains a length of about a foot, two-thirds of which are occupied by the
long and cylindrical tail, has a short and frog-like head, raised into curved rid
over the eyes, with the muzzle very blunt, and the lower jaw longer than the
upper. The skin of the neck is curiously puckered inferiorly, the folds formin
a pair of pouches on the sides, although there is no pouch on the throat. I
form, the body is at most but slightly compressed, with a low and slightly serrated
crest running from the nape down to the back; and the uniform scales of the
back are small and overlapping, and those on the top of the head enlarged. The
long and bent toes are markedly compressed, and are furnished with short but
strong claws. In coloration this species is one of the handsomest of its tribe. The
general ground-colour of the upper-parts is reddish or purplish brown, ornamented
with more or less distinctly defined blackish transverse bars ; a broad black band
traverses the fold in front of the shoulder, and may extend across the nape ; while




IGUANOID GROUP.



*35



frequently in front of this band there is a large yellowish orange spot on each side
of the neck. Below, the colour is brownish or yellowish, which may be either
uniform or clouded with brown markings. An inhabitant of the great primeval
forests of South America, the stilted lizard has the power of changing colour,
and is consequently often designated a chamseleon. It generally associates in
pairs, dwelling among trees, and its food appears to be entirely of a vegetable
nature. When disturbed, it rushes suddenly up a high branch, where it stands
with outstretched head and neck and widely open eyes, gazing steadily at the
intruder. Should it be unable to escape otherwise, the creature raises its neck still
higher, inflates the neck-pouches, and, with a sharp cry, springs boldly into the air.
There are a very large number of genera, agreeing with those hitherto noticed




The Sea-Lizard.



in the absence of pores on the thighs, which the limits of our space prevent us from
even mentioning. We accordingly pass on to the consideration of certain repre-
sentatives of the second great group of the family, in which such pores are present.
Both as regards their fauna and flora, the Galapagos Islands
stand altogether apart from the rest of the world, the greater number
of their animals and plants being absolutely peculiar, it may be specifically, or it
may be generically, -while herbivorous reptiles take the place occupied on the
continents of the world by vegetable-eating mammals. In no case, however, is
this faunistic peculiarity more marked than in the occurrence in such a limited
area of two distinct genera of the present family, each represented by a single
species. Remarkable alike for special features connected with their dentition, as
well as for their large bodily size, these two lizards differ widely from the rest
of the family. Whereas, however, the one is a land animal, the other is unique



I 3 6



LIZARDS.



among the entire suborder to which it belongs in being a marine creature,
subsisting on seaweeds.

Agreeing with the great majority of that section of the family characterised
by the presence of pores on the thighs in the fourth hind-toe being longer than the
third, the sea-lizard, together with the terrestrial species inhabiting the same islands,
differs from all the rest in that the front teeth resemble those of the cheek-series in
having three-cusped crowns, so that the entire set of teeth is uniform in character.
From its terrestrial ally, the sea-lizard (Amblyrhynchus cristatus) is distinguished
by its much compressed and crested tail, as well as by the presence of an incipient




GALAPAGOS SEA-LIZARD (i Hat. si/A').



web between the toes. This lizard is the largest member of the family, and attains
a total length of some 53 inches. It is characterised by the compressed form of the
body and tail, and the extremely short and truncated head. A well-marked crest
runs from the nape of the neck to the tip of the tail, and the whole build of the
animal is stout and "chubby." The throat is devoid of a pouch, although it has
a well-marked transverse fold, and the toes are laterally compressed. In the small
and convex head the nostrils are situated near the end of the muzzle, the eye and
aperture of the ear are alike small, and the upper surface is surmounted by a
number of conical spine-like shields of relatively large size. The investing scales
of the body are small, and although keeled on the back, are smooth below. In the.
stoutly-made limbs the toes are rather short, the third one in the hind-foot being



IGUANOID GROUP.



137



strongly serrated on its inner border of its basal joint. The compressed and crested
tail is about equal to one and a half times the length of the head and body, and is
covered with equal-sized keeled scales. In colour this lizard is black or blackish
brown above, with the abdomen and the inner surfaces of the thighs not unfrequently
of a dirty white. In the young state, however, the upper-parts are brown with
paler spots, and more or less distinctly marked dark crossbars on the back. In
weight, full-grown examples reach as much as 20 Ibs.

The sea-lizard is extremely common on the rocky coasts of the various islands
of the Galapagos Group, but is seldom found more than some ten yards from the
shore. Of its habits Darwin writes that " this lizard swims with perfect ease and
quickness by a serpentine movement of its body and flattened tail the legs being
motionless and closely collapsed on its sides. A seaman on board sank one, with a
heavy weight attached to it, thinking thus to kill it directly; but when, an hour
afterwards, he drew up the line, it was quite active. Their limbs and strong claws
are admirably adapted for crawling over the rugged and fissured masses of lava,
which everywhere form the coast. In such situations, a group of six or seven of
these hideous reptiles may oftentimes be seen on the black rocks, a few feet above
the surf, basking in the sun with outstretched legs." After mentioning that the
stomachs of several examples that were examined contained finely minced seaweed,
and also observing that the droves seen swimming out to sea were doubtless in
search of food of this nature, the same author proceeds to state that, when frightened,
these lizards absolutely refuse to enter the water. " Hence," he continues, " it is
easy to drive these lizards down to any little point overhanging the sea, where they
will sooner allow a person to catch hold of their tails than enter the water. They
do not seem to have any notion of biting, but when much frightened they squirt a
drop of fluid from each nostril. I threw one several times as far as I could into a
deep pool left by the retiring tide, but it invariably returned in a direct line to the
spot where I stood. It swam near the bottom, with a very graceful and rapid
movement, and occasionally aided itself over the uneven ground with its feet. As
soon as it arrived near the edge, but still being under water, it tried to conceal
itself in the tufts of seaweed, or it entered some crevice. As soon as it thought the
duiiger was past, it crawled out on the dry rocks, and shuffled away as quickly as
it could. I several times caught the same lizard by driving it down to a point, and,
though possessed of such perfect powers of diving and swimming, nothing would
induce it to enter the water ; and as often as I threw it in, it returned in the manner
above described. Perhaps this singular piece of apparent stupidity may be accounted
for by the circumstance that this reptile has no enemy whatever on shore, whereas
at sea it must often fall a prey to the numerous sharks." Later observers have
borne testimony to the extraordinary numbers in which the sea-lizards are to be
met with in the Galapagos, and likewise as to their food consisting mainly of broad-
leaved sea-leaves.

Galapagos Although originally included in the same genus as its aquatic

Land-Lizards. CO usin, there seems no doubt that the land-lizard of the Galapagos

(Conolophus subcristatus) is entitled to stand as the representative of a distinct

generic group ; the nearly cylindrical tail and perfectly free toes being distinctive

characters which cannot well be overlooked. Not reaching within some 11 inches



138 LIZARDS.

of the dimensions attained by the last, this lizard is likewise a stoutly - built
creature, with the rather small head slightly longer than broad, the body some-
what depressed, a slight spiny crest on the nape, continued as a low ridge
on the back, and the scales of the latter small and keeled, while the slightly
larger ones on the lower surface are smooth. Although devoid of a pouch,
and with but a very slight transverse fold, the throat is strongly plicate
longitudinally, and is covered with minute granules. The stout limbs terminate in
very short toes, of which the third in the hind-foot is serrated on the inner margin




GALAPAGOS LAND-LI/ARD (J nat. size).

of its basal joint. On the thigh the pores are arranged in a long series, and vary
from seventeen to twenty-one in number. In length the tail scarcely exceeds the
head and body, while in form it is slightly compressed, having a low ridge
superiorly, and being covered with small keeled scales of uniform si/e. In general
colour the creature is dark In-own, with the head and under-parts lighter.

These lizards are confined to the central islands of the Galapagos (Jroup, such
as Albemarle and James Islands, where they are found in great numbers in the
low barren districts near the coasts, although also met with in the elevated damp
regions of the interior. On James Island Darwin found them so numerous, that
it was difficult to obtain a spot free from their burrows on which to pitch a tent.
Attaining a weight of from 10 to 15 Ibs. .these lizards are lazy and sluggish
in their movements, crawling slowly along with their bellies and tails dragging on



1GUANOID GROUP. i 39

the ground, and often stopping for a minute or two to doze with closed eyes, and
tin- hind-limbs stretched out on the arid soil. According to Darwin's account,
" they inhabit burrows, which they sometimes make between fragments of lava,
but more generally on level patches of the soft sandstone-like tufa. The holes do
not appear to be very deep, and they enter the ground at a small angle; so that
when walking over these lizard-warrens, the soil is constantly giving way, much
to the annoyance of the tired walker. This animal, when making its burrow,
works alternately the opposite sides of its body. One front-leg for a short time
scratches up the soil, and throws it towards the hind-foot, which is well placed so
as to heave it beyond the mouth of the hole. That side of the body being tired,
the other takes up the task, and so on alternately .... They feed by day, and
do not wander far from their burrows; if frightened, they rush to them with a
most awkward gait. Except when running downhill, they cannot move very
fast, apparently from the lateral position of their legs. They are not at all
timorous ; when attentively watching anyone, they curl their tails, and, raising
themselves on their front-legs, nod their heads vertically, with a quick movement,
and try to look very fierce ; but in reality they are not so at all ; if one just stamps
on the ground, down go their tails, and off they shuffle as quickly as they can."
If worried with a stick, these lizards will bite it severely; and when two are held
together on the ground, they will fight and bite till blood flows. " The individuals,
and they are the greater number, which inhabit the lower country, can scarcely
taste a drop of water throughout the year; but they consume much of the
succulent cactus, the branches of which are occasionally broken off by the wind.
I several times threw a piece to two or three of them when together ; and it was
amusing enough to see them trying to seize and carry it away in their mouths,
like so many hungry dogs with a bone." They also eat the leaves of several trees,
more especially of an acacia, to obtain which they ascend the low stunted trees, on
the boughs of which they may often be observed quietly feeding. The females lay
large eggs of an elongated form in their burrows ; both these and the flesh of the
lizards themselves being eaten by the inhabitants of the Galapagos.

The time iguanas, of which there are two closely-allied species
True Iguanas.

from Tropical America and the West Indies, differ from the two pre-
ceding genera in that the edges of the crowns of the cheek-teeth are serrated, while
the front teeth are simply conical. The distinctive features of the iguanas are to be
found in the long and much compressed body, the large four-sided head, covered above
with enlarged scales, the short neck, powerful limbs, long-toed feet, and the much
elongated tail, upon which the scales are uniform and keeled. The throat is
furnished with a large non-dilatable appendage, in front of which is a crest of large
compressed scales ; and a continuous crest of long spines runs from the nape along
the back, and is continued as a ridge on the tail. The scales on the back are small,
equal, and keeled; the neck has some scattered large conical or bluntly -keeled
tubercles, and there are also some large tubercular scales on the sides of the throat,
more especially one below the aperture of the ear ; while on the under-parts the
scales are either smooth or slightly keeled. The pores on the thighs are numerous,
and, in addition to those in the margins of the jaws, there are teeth on the pterygoid
bones of the palate. The common iguana {Iguana tuberculata) attains a length



1 40 LIZARDS.

of as much as a yard and a half, two-thirds of which are occupied by the tail. The
general colour is green or greenish, becoming lighter on the under-parts ; but the
upper surface may be either uniform, or variegated with darker brownish bands,
the flanks usually having light-edged vertical dark bars, while the tail has more
or less distinct dark rings. There is frequently a whitish band in front of the
arm, and some of the large tubercular scales on the sides of the throat and neck
are often light-coloured.

Both species of iguanas, of which there are several varieties, are essentially
arboreal lizards, generally frequenting those regions of the forests where the trees
overhang the water. Here they move with great agility, climbing or springing
from bough to bough, while the harmony of their coloration to their surroundings
renders them well-nigh invisible. Towards evening they not unfrequently descend
to the ground to feed; but, when frightened, immediately rush to the topmost
boughs of the trees, or plunge headlong into deep water. In the latter element
they are, indeed, perfectly at home, and swim strongly and swiftly, with their limbs
closely applied to their bodies, and impelled by their powerful tails. They are
likewise expert divers, frequently remaining for a considerable time below the
surface ; their activity in the water being such that they are able to avoid all
enemies save crocodiles and caimans. Their chief food consists of leaves, flowers
and berries, although they will also eat insects; the numbers of small worms
sometimes found in their stomachs having probably been swallowed accidentally.
Generally seeking to escape at once from human beings, iguanas when unable to
flee show fight, erecting their heads and assuming a fierce aspect, while at close
quarters they bite savagely and administer severe blows with their powerful tails.
The female deposits from eight to seventeen eggs in a hole dug in sandy soil, but
as several individuals will not unfrequently lay together, as many as ten dozen
eggs may be found in a single nest. In spite of their somewhat repulsive appear-
ance, iguanas are hunted for the sake of their flesh, which is white in colour and
delicate in flavour, and is said to resemble the breast of a chicken. The eggs also,
which consist almost entirely of yolk, are highly esteemed as articles of diet.
Iguanas are generally captured by means of nooses, which are thrown over their
heads as they repose on the branches. The much smaller horned iguana (M^do-
poceros cornutus), of San Domingo, constitutes a separate genus, distinguished by
the presence of an inflatable pouch on the throat.

Ring-Tailed The West-Indian ring-tailed iguana (Cyclura carinata) is selected

Iguana. to represent a group of genera distinguished from the foregoing by
the crowns of the cheek-teeth being three-cusped or simply conical. While four
of these genera among which is the Fijian iguana (Brachylophus /J'*r/<////x)
are characterised by the shortness of the row of pores on the thigh, the present
species is one of those in which they form a long series; and it is further char-
acterised by the presence of a serrated crest down the back and tail, and also
of a pouch and slight transverse fold on the throat. The head is large, swollen
below the ears, and furnished with enlarged scales on the snout ; while the body
and tail are compressed, the body being covered with small scales. The species
derives its name from the rings of keeled scales which form regular segments on
the sides of the tail ; each segment being composed of from three to five series of



IGUANOID GROUP.



141



small scales, and a single series of larger and somewhat spinous ones. The toes
are compressed, and covered below with keeled plates. In total length this iguana
reaches about 48 inches ; and its general colour is green or dark olive, speckled
with darker and lighter, and frequently marked with blackish transverse bands.
The ring-tailed iguana is a somewhat local species, occurring most abundantly in
Jamaica, on the limestone mountains in the neighbourhood of Kingston Harbour
and Goat Island, but also met with on the low grounds lying between the coast
ranges and the higher mountains of the interior, where hollow trees occur. Shy
and retiring in their habits, the creatures live in pairs, and display no great partiality




RING-TAILED IGUANA (\ 11 at. size).

J or water, although, on occasion, they can swim as well as the true iguanas. They
feed mainly or entirely on grass, and when disturbed in grazing, these reptiles
rush back to the trees with extraordinary speed, sometimes taking great leaps like
a frog, although their movements are generally deliberate and slow. If unable to
escape, they show fight in much the same way as the true iguanas. The breeding-
habits of this species do not appear to be known, although the females of the allied
black iguana (Ctenosaura acanthura) of California are in the habit of laying in
company, like the true iguanas. The ring-tailed iguana exhales a peculiarly dis-
agreeable smell, which is stated to be so objectionable as to cause even the ants to
forsake a room into which one of these creatures is brought. For this reason its
flesh is uneatable, although that of the black iguana is highly esteemed.



i 4 2 LIZARDS.

We have not hitherto mentioned that the vertebrae of the
l8 ' iguanoid lizards differ from those of the agamoids and most other
members of the suborder in being furnished with additional articular facets like
those of snakes. Vertebrae of this peculiar type occur in the upper Eocene rocks
of England and the Continent, and have been provisionally assigned to the typical
genus Iguana, although it is more likely that they indicate an extinct genus.
Somewhat similar vertebrae from the corresponding strata of the United States
have been described under the name of Iguanavus.

The last and at the same time the most peculiar members of the

present family are the horned lizards of North America and Mexico,

which may be regarded as the representatives of the moloch lizard among the

agamoids. From their short, rounded heads, abbreviated bodies, and shorten* M!




HORNED LIZARD (f nat. size).

tails, coupled with a general batrachian appearance, these lizards are commonly
termed toads in America, the popular name of the figured species (Phrynosoma.
comutum) being the Californian toad. Strange, not to say ugly, in appearance
these lizards are at once distinguished from all their allies by the presence of
several bony spines projecting from the back of the shortened head, and of tubercles
or spines scattered among the ordinary scales of the body. In form, the bo.dy is
broad and depressed, without any crest down the back; and the tail is very
thick at the base, and never longer than the body. The limbs are rather long,
with pores on the thighs, and keeled plates on the lower surfaces of the toes.
From most other members of the family these lizards are further distinguished
by the absence of teeth on the palate. Of the twelve species of the genus (.In-
best known is the common horned toad, herewith figured, which lias the tail longer
than the head, distinct spines on the back, and (lie drum of the ear naked. Its
general appearance is even more than superficially toad-like, the head being as



GIRDLED LIZARDS. 143

broad as long, and the body remarkable for its extreme plumpness. Measuring a
little over 5 inches in length, this species is rather handsomely coloured. Above,
the ground-colour is greyish or brownish, with a more or less well-marked light
stripe down the back, and dark brown spots at the bases of the larger spines ;
while there are likewise markings of the same colour on the nape and head.
Beneath, the hue is yellowish, with or without a few small brown spots. In two
species of the genus (e.g. P. taurus) the tail does not exceed the head in length.
The common species is found locally in sandy districts both on the plains and
mountains, and is in some places abundant, although from its coloration frequently
3scaping notice. In spite of its somewhat formidable appearance, it is a harmless
creature, not attempting to bite even when captured. Lacking the protrusive
tongue of the chamseleon, and being debarred by its clumsy form from running
Cast, the horned lizard is unable to capture the swifter insects, and consequently
preys upon sand-haunting beetles, whose speed is inferior to its own ; such prey
being generally captured in the evening, and the creature lying passive on the
sand during the day. Some species of horned lizards are remarkable as being



Online LibraryRichard LydekkerThe new natural history (Volume 5) → online text (page 16 of 62)