B 3 300 ^

GUIDE

TO THE

EEPTILES AND BATKACHIANS

EXHIBITED IN THE

DEPARTMENT OF ZOOLOGY

OF THE

BEITISH MUSEUM (NATURAL HISTOEY),

CROMWELL ROAD, LONDON, S.W. 7.

|

ILLUSTRATED BY 5O FIGURES.

THIRD EDITION.

LONDON:

PRINTED BY ORDER OF THE TRUSTEES.
1922.

All rights reserved.
PRICE ONE SHILLING.

GUIDE

TO THE

EEPTILES AND BATBACHIANS

EXHIBITED IN THE

DEPABTMENT OF ZOOLOGY

OF THE

BRITISH MUSEUM (NATURAL HISTORY),

a 7

CKOMWELL ROAD, LONDON, S.W. 7.

ILLUSTRATED BY 5O FIGURES.

THIRD EDITION.

LONDON:
FEINTED BY ORDER OF THE TRUSTEES.

1922.

All rights reserved.

PRINTED IN ENGLAND

AT THE OXFORD UNIVERSITY PRESS

BY FREDERICK HALL

PREFACE.

THE Reptile Gallery is mainly devoted to the exhibition of
recent Reptiles and Batrachians, but a few characteristic
examples of each of the more important extinct groups are
included. In addition the great Dinosaurs Diplodocus, Iguanodon,
and Tricemtops are placed heie because room could not be found
for them in the Gallery of Fossil Reptiles.

The National Collection of Reptiles and Batrachians comprises
about 70,000 specimens, representing most of the known species,
which number nearly 9.000. The majority of these specimens
are preserved in spirit, and examples of selected species only are
shown in the Gallery.

Thanks are due to Messrs. Macmillan & Co., Ltd., for permis-
sion to reproduce a number of illustrations from the Cambridge
Natural History : the process-blocks are from photographs of
specimens in the Museum.

C. TATE REGAN,

Keeper of Zoology.
BRITISH MUSEUM (NATURAL HISTORY),

LONDON.
March 1922.

498296

TABLE OF CONTENTS.

PAGE

BATRACHIANS . ... . . . . 7

UBODELA (SALAMANDERS AND NEWTS) . . ... 8

APODA (CoECiLiANs) . . . . . .11

ANURA (FROGS AND TOADS) . . . .- .12

REPTILES . . . . . . . 17

RHYNCHOCEPHALIA (TUATERA) . . . . .19

CROCODILIA (CROCODILES AND ALLIGATORS) . , .19

CHELONIA (TORTOISES AND TURTLES) . . . .20

SQFAMATA (LIZARDS AND SNAKES) . . . ' .31

INDEX 53

GUIDE

TO THE

REPTILES AND BATRACHIANS.

BATRACHIANS.

(Table-case near south end of Gallery.}

THE class Batrachia, or Amphibia, includes Frogs, Newts, &c.
The earliest members of the group, found in the Carboniferous
strata, closely approximate in structure to the bony fishes of the
extinct order Rhipidistia, from which they were doubtless
derived ; but they differed from them, and from all other fishes,
in several characters, of which the most important is that instead
of paired fins they were provided with legs ending in five -toed
feet. These were the earliest terrestrial four-footed vertebrates,
from which have arisen not only the modern Batrachians but
also the Reptiles, and through the latter the Birds and Mammals.
A few examples of these primitive Batrachians are exhibited ;
they were mostly newt-like in form, but had the skull roofed by
dermal bones : hence the ordinal name Stegocephala.

Modern Batrachians agree with modern Reptiles in being cold-
blooded, but differ from them in having the skin naked instead
of scaly, and by the skull articulating with the first vertebra by
two knobs, ' occipital condyles,' instead of one.

Batrachians generally commence their life as truly aquatic
creatures, breathing the air dissolved in the water by means of
gills, and later become terrestrial, breathing atmospheric air by
means of lungs, whereas Reptiles breathe by lungs throughout
their life. A few Batrachians, however, are permanently aquatic
and retain their gills throughout life, and there are some which,
when adult, manage to breathe without either gills or lungs ;
moreover, there are forms in which the young make their first
appearance in an advanced stage of development and pass through
the gilled larval stage in the egg or within the body of the parent.
Batrachians inflate their lungs by swallowing air, having no
mechanism for expanding the chest.

The number of living species of Batrachians does not greatly
exceed 2,000. These are placed in three orders, Urodela or
Tailed Batrachians (Newts, Salamanders, &c.), Apoda or Limbless
Batrachians (Coecilians), and Anura or Tailless Batrachians
(Frogs, Toads, &c.).

8 Guide to Reptiles and Batrachians.

Order I. URODELA.

The Urodela, or Tailed Batrachians, are characterized by
having a tail and at least the front pair of limbs. The young
are provided with uncovered gills, which generally disappear in
the adult, but in some permanently aquatic forms may be retained
throughout life. The group is a small one, numbering about
200 species, mostly from Europe, Northern Asia, and North
America ; a few species occur in Central America and in the

FIG. 1.

The Common Smooth Newt (Molge vulgaris). Male and female.

Andes, extending southwards to Peru. Not many species grow
to a greater length than 6 inches.

Nearly all the Urodela belong to the family Salamandridae.
These have two pairs of limbs, teeth in the jaws, and movable
eye-lids ; with one remarkable exception there are no gills in
adults. A curious feature of several members of the family is
the absence of lungs, respiration being effected by the skin and
the pharynx.

Newts (Molge or Triton) are found in Europe and Northern
Asia ; they have the tail strongly compressed and often furnished

Salamanders and Newts.

9

with a fin, There are three British species, in all of which the
breeding males develop a high crest on the back. Newts are
terrestrial : they prefer cool and moist places, and feed on insects,
worms, &c. ; in winter they hibernate. At the breeding season
they make their way to ponds and become aquatic for a time ;
the eggs are laid and the young live in the water.

The genus Salamandra includes three species, the Spotted
Salamander (S. maculosa) from Europe and Asia Minor, the
Alpine Salamander (S. atra) of the Alps, and the Caucasian
Salamander (8. caucasica) ; they have a rounded tail. The
Spotted Salamander is noteworthy for its black and yellow

FIG. 2.

The Axolotl : the egg-laying larval form of Atnblystoma tigrinum. Mexico.

coloration and for the poisonous properties of a fluid which
exudes from its skin. The Salamanders prefer hilly country,
where they hide under moss or stones ; they are viviparous.
In the Spotted Salamander the mother partly enters the water in
the spring to produce her young, which may number up to 50
and are about an inch long when born ; they lose their gills and
become terrestrial before the winter. Embryos of the Alpine
Salamander are exhibited ; this species produces only two young
at a birth, which are much larger than the young of the Spotted
Salamander and are essentially similar to their parents.

Amblystoma includes a number of species from North America ;
they bear a general resemblance to the European Salamanders
and live in much the same way. The famous Axolotl of the lakes
near the city of Mexico is thoroughly aquatic, and is provided
with three pairs of external gills and a well -developed median fin

10

Guide to Reptiles and Batrachians.

both above and below ; it may grow to a length of one foot.
Specimens brought to Europe laid eggs which developed into
Axolotls, some of which lost their gills and fins, left the wrater,
and were found to have changed into the common terrestrial

FIG. 3.

FIG. 4.

The Three-toed Salamander
(Amphiuma means).

The Olm (Proteus anguinus),
from the caves of Carniola.

species Amblystoma tigrinum, of which the Axolotl was thus
proved to be a permanent larval form.

Other important American genera are Desmognathus, Plethodon,
and Spelerpes, the last being represented in Europe by S. fuscus

Salamanders and Newts. 11

of Italy and Sardinia, which lives in shady places, lying in wait
for insects, which it catches by the sudden protrusion of its long
tongue.

The Amphiumidae differ from the Salamandridae in having no
eye-lids. The Giant Salamander (Megalobatrachus maximus) of
China and Japan grows to a length of 5 feet ; it is strictly
aquatic, inhabiting small mountain streams, where it often lies
hidden under rocks ; it feeds on fishes, worms, &c., and as it will
readily take a bait it is caught for food. An extinct Giant
Salamander is known from the Miocene of Baden. The North
American ' Hellbender ' (Cryptobranchus alleghaniensis) is very
similar to the Asiatic species, but differs in having a gill-opening ;
it grows to only 18 inches long. Amphiuma includes two species
from North America, which differ from the preceding in their
eel-shaped body and small limbs, with only two or three toes ;
these animals inhabit swamps and often burrow in the mud.

The Proteidae differ from the Amphiumidae in having no
maxillary bone and in the persistence of the gills throughout
life. Necturus maculatus is found in the Mississippi and the
Great Lakes ; it has well -developed four-toed limbs and func-
tional eyes ; its colour is brown, with irregular blackish spots.
The other two members of the family are subterranean and
differ from Necturus in being white, and in having their eyes
concealed beneath the skin. Typhlomolge raihbuni of Texas has
rather long and slender limbs, the front pair with four and the
hind pair with five toes ; all the known specimens have come up
with the water of an artesian well. Proteus anguineus, the ' Olm '.
from the subterranean waters of the Eastern Alps and Dalmatia,
has shorter limbs, with three front and two hind toes. There
can be little doubt that Typhlomolge and Proteus have evolved
independently from .^ec^ms-like ancestors, the concealed eyes
and the absence of pigment from the skin being due to their life
in total darkness.

The Sirenidae retain their gills throughout life, but are distin-
guished from the Proteidae by their eel-shaped body, the absence
of hind-limbs, and the toothless jaws. Siren lacertina is the
Mud-eel of the south-eastern United States ; it lives in ponds
and^ditches, burrowing in the mud.

Order 2. APODA.

4i

The Limbless Batrachians, or Coecilians, are worm-like in
appearance and in their mode of life, burrowing in moist ground ;
they feed on worms, &c. The skin is slimy and forms a number of
transverse folds or rings ; it may contain small embedded scales.
The eyes are small and subcutaneous, but between the eye and
the nostril is a soft protrusible tentacle, probably tactile in

12

Guide, to Reptiles and Batrachians.

FIG. 5.

function. The scales in the skin, and certain features of the
skeleton, indicate that if the Apoda are derived from the Urodela
they have arisen from some group more generalized in structure
than the living members of that order.
About 200 species are known, from tropical
America, Africa, and Southern Asia ; most
of these are small, few attaining a length
of 18 inches. Their life-history is imperfectly
known, but the species studied include vivi-
parous forms and others in which the gilled
stage is passed through in the egg. In
Ichihyophis glutinosa of Southern Asia the
female coils herself round the eggs, which
are laid in a hole near running water, to
which the young take when they are hatched,
although they have lost their gills ; they
are, however, provided with a tail-fin which
disappears before they become terrestrial.
The species exhibited are Coecilia gracilis
and Siphonops annulatus, both from South
America.

Order 3. ANURA.

The Anura, or Frogs and Toads, are char-
acterized by the absence of the tail ; they
have well-developed limbs, the hind ones
being the longer ; the front pair generally
have four toes and the hind pair five. In
the skeleton the vertebral column is very
short and the posterior vertebrae are fused
to form a long spine, which lies between the
elongate and backwardly directed iliac bones.
Nearly all Frogs and Toads have a long pro-
tractile tongue, with which they catch the
worms, insects, &c. on which they feed, and
most of them produce croaking sounds
in the larynx, intensified in the males
by the distension of the vocal pouches,
which are connected with the mouth and
act as resonators.

As a rule the eggs are laid in water, often
in masses or strings, which either float or
may be attached to weeds or stones ; the
larvae develop into tadpoles, in which the head is not marked off
from the swollen body, which contains a long intestine coiled like
a watch-spring, the tail is well developed, the gills are covered by
an opercular fold, the small mouth is surrounded by funnel-

A Limbless Amphibian

( Uraeotyphlus

africanus).

Frogs and Toads.

13

shaped lips studded with horny teeth and the jaws are provided
with horny beaks. The transformation of the aquatic tadpole
into the terrestrial adult form involves the development of the
limbs and lungs, the reconstruction of the intestine, the loss of the
tail, gills, lips, and horny beaks, the widening of the mouth, &c.
A tadpole of Pelobates is exhibited and a series of specimens of

FIG. 6.

A Female Surinam Toad (Pipa americana) with young emerging from
the brooding pouches of the back.

Pseudis paradoxa illustrate the change from a tadpole into a frog.
In some forms the eggs are relatively few and large and are
protected by the parent ", the young emerging at an advanced
stage of development, sometimes even as miniature frogs.

The number of known species of Frogs and Toads is nearly
2,000 ; they are found in all tropical and temperate countries.
The Anura may be divided into three main groups, Aglossa,
Arcifera and Firmisternia.

14 Guide to Reptiles and Batrachians.

The Aglossa are characterized by the absence of a tongue,
which is connected with their aquatic habits, a tongue not being
needed by creatures which S3ize their prey under water. There
are three genera, Xenopus and Hymenochirus from Africa and
Pipa from South America. The species of Xenopus are known as
' Clawed Toads ' from the sharply pointed nails of the first three
hind-toes. The Surinam Toad (Pipa americana) is remarkable in
that the female carries the eggs on her back, where they are
placed in position by the male and sink into the soft spongy skin,
so that each egg occupies a pouch, in which the development takes
place, until the young emerge as fully formed Toads.

The Arcifera are characterized by the presence of a tongue, and
by the overlapping of the coracoid bones on the chest. The most
primitive family is the Discoglossidae, which agree with the
Aglossa in having ribs, and differ from all other Anura in having
the tongue round and non-protrusible. The half-dozen species of
this family are the remnants of an old and widely distributed
group ; Liopelma is the only Batrachian found in New Zealand ;
the rest occur in Eurasia and North America. European examples
are the Fire-bellied Toad (Bombinator igneus), a poisonous species
with bright ' warning ' colours, and the Mid- wife Toad (Alytes
obstetricans), the male of which carries the strings of eggs round his
hind-limbs ; when the eggs are ready to hatch, he takes to the water.

The Arcifera without ribs, with a protractile tongue, and with
the terminal bones of the digits not claw-shaped, have been
grouped into several families, Bufonidae, Pelobatidae, Cystigna-
thidae, &c., but these are badly defined and unnatural. There are
two British Toads, the Common Toad (Bufo vulgaris), which
ranges throughout Europe and Northern Asia, but is absent from
Ireland, and the Natterjack (B. calamita), which is found in
Western Europe, in some parts of England and Wales, and in
Kerry in Ireland. The skin of the Common Toad is studded with
wart-like prominences, from which a poisonous slime may exude ;
this makes it distasteful to eat, but is not used for offensive
purposes. Bufo marinus is a very large Toad, attaining a length
of six inches ; it inhabits Central and South America.

The Spade-footed Toad (Pelobates fuscus] of Europe is provided
with a sharp spur on each hind-foot, which it uses for digging,
concealing itself in the sand very quickly. The Horned Toads
(Ceratophrys) of South America have the eye-lids produced into
a pair of appendages which resemble horns. Leptodactylus of
Tropical America has long and slender legs.

The Hylidae, or Tree-Frogs, differ from the Bufonidae in having
adhesive disks at the ends of the digits ; these disks are supported
by the claw-shaped terminal phalanges. Most of the Hylidae are
American or Australian, but three species of Hyla are found in
Europe and Northern Asia. The characteristic colour of these

FLO. 7.

The Horned Toad (Cemtophrys cornuta), Brazil ; reduced.

FIG. 8.

The Pouched Frog (Nototrema marsupiatum), with eggs in pouch. Ecuador.

16

Guide to Reptiles and Batrachians.

arboreal Frogs is green. In Nototrema of South America the
female carries the eggs in a pouch on the back.

In the Firmisternia the coracoids do not overlap, but meet
and are firmly united in the middle line of the chest. Ribs are
absent and the tongue is protractile. Several families have been
recognized, Ranidae, Dendrobatidae, Engystomatidae, &c., but
they are not yet satisfactorily denned.

FIG. 9.

The Common Frog (Rana temporaria).

The genus Rana includes the Common Frog (R. temporaria),
the Edible Frog (R. esculenta), and the North American Bull-
Frog (R. catesbiana), which takes its name from the loud ro ng
noise produced by the assembled males in the breeding season.
R. guppyi of the Solomon Islands is a large frog which feeds
on crabs, but R. goliath of W. Africa is still larger, attaining
a length of nearly a foot (not including the limbs). The Horned
Frog (Ceratobatrachus guentheri) of the Solomon Islands is
remarkable for its enormous mouth, with teeth in both jaws.
Rhacophorus includes a number of species from Madagascar and
Southern Asia, arboreal frogs with adhesive disks at the ends of
the digits, which are webbed ; some species with large and com-
pletely webbed feet are said to use them as parachutes. The
Engystomatidae have a small toothless mouth and a sharp snout ;
they eat ants and are found in tropical countries. The Dendroba-
tidae are arboreal.

Reptiles

17

REPTILES.

REPTILES may be defined as cold-blooded vertebrates which
breathe by lungs throughout life, having no aquatic larval stage.
Modern Reptiles are distinguished from, modern Batrachians by
having the skin covered with scales and by the single occipital
condyle. The living Reptiles, although more numerous than the
Batrachians, are but a remnant of a group which was once
dominant, but has now been replaced bv the Mammals and
Birds.

The earliest Reptiles, the Cotylosauria, made their appearance
in Carboniferous times ; they were extremely similar to the
Batmchia Stegocephala, from which they were derived, and from
which it is not easy to separate them. " The Anomodontia of the
Permian and Triassic epochs were a large and varied group of

FIG. 10.

Restoration of a Long -tailed Pterodactyle (Rhamphorhynchus phyllurus), from
the Upper Jurassic Lithographic Stone of Bavaria ; £ nat. size.

terrestrial Reptiles, from which the Mammals originated ; some
of them, e. g. Aelurognathus, are remarkable for their specialized
carnivorous dentition. The Dinosauria flourished during the
Mesezoic or Secondary period of geological history (Triassic,
Jurassic, and Cretaceous strata), and included both herbivorous
and carnivorous forms. The skeleton of Diplodocus is the most
conspicuous object in the gallery ; this gigantic Dinosaur from
the Jurassic of Wyoming measures eighty-four feet nine inches in
total length ; it was probably too heavy for much activity on
land and may have spent most of its time in the water, feeding on
water-plants, its long neck and the position of the nostrils at the
top of the skull enabling it to breathe when wading at considerable
depths. Other large Dinosaurs exhibited are Triceratops, with its
bony neck-shield, and Iguanodon, which walked on its hind-legs.

Tuatera. 19

The Ichthyosaurs and Plesiosaurs were whale -like marine
Reptiles, with the limbs modified into paddles. The Cretaceous
Mosasaurs also had paddle-shaped limbs, but were snake-like
in form ; Liodon is estimated to have reached a length of 100 feet,
a veritable Sea-serpent. The Pterodactyles were flying Reptiles,
with the membrane of each wing attached to the body and
supported by the elongate outermost digit of the fore-limb ;
they have no affinity to Birds. Some species of Pteranodon had a
wing-spread of twenty feet ; a fine example is exhibited on the
west wall of the gallery, above the door.

All the orders mentioned above became extinct millions
of years ago, long before man appeared. The specimens exhibited
in cases 4, 5, 16 and 17 give some idea of the structure and
appearance of these inhabitants of the land, the sea, and the air
during the Secondary Period, the ' Age of Reptiles ' as it has been
called ; they may be studied in more detail in the Gallery of
Fossil Reptiles.

About 6,500 species of Reptiles are living at the present day ;
they belong to four orders, Rhynchocephalia, Crocodilia, Chelonia,
and Squamata.

Order 1. RHYNCHOCEPHALIA.

(Case 5.)

The Tuatera (Sphenodon punctatus) of New Zealand was
formerly classed with the lizards, but it differs from them in
having two horizontal bony arches on each side of the temporal
region of the skull, in the fixed quadrate (the bone with which the
lower jaw articulates), and in many other features ; it is now
recognized as the most primitive of all living Reptiles and the
sole survivor of a group which dates back to Triassic times.

The Tuatera is like a Lizard in appearance, and attains a
length of more than two feet ; it has been exterminated on the
mainland, but still lives on a few small islands near the coast.
It excavates a burrow, which it often allows a petrel to share,
without attempting to molest the bird or its eggs and young ; it
sleeps most of the day, but at night ventures out in search of food,
which consists of small living animals. The eggs have a hard,
white shell ; about ten are laid in holes in the sand, in a sunny
place ; they do not hatch until a year has passed.

Order 2. CROCODILIA.

(Cases 1 to 3.)

The members of this order are large, four-footed' long-tailed
Reptiles, with five toes to the fore-feet and four to the hind ones.
The teeth are implanted in separate sockets, the quadrate bone

B 2

20 Guide to Reptiles and Batrachians.

is fixed, and the bones of the skull are sculptured. The body is
covered with horny shields, beneath which, at least on the back,
are series of bony plates. The inner aperture of the nostrils is
placed far back on the palate, enabling these animals to breathe
while holding their prey under water.

There are about two dozen living species ; these frequent
rivers, but their mesozoic ancestors appear to have been marine,
and approximate in structure to the Dinosaurs.

In the genus Crocodilus the snout is short or moderately long,
and is rounded or pointed ; the teeth are large and stout, and
the fourth lower tooth fits into a notch in the upper jaw, being
exposed when the mouth is closed. Crocodiles occur in America
from Florida to Guiana ; in the old world they inhabit Africa.
Madagascar, and Southern Asia, extending through the Archi-
pelago to the Solomon Islands and northern Australia. Crocodiles
are large and ferocious ; they are exclusively carnivorous, and
generally seize their victims (other than human beings) by the
nose as they are drinking. A large number of people — especially
women, as they go to the rivers for water — are annually killed
in India by these Reptiles. Crocodiles bury their eggs, which
have a hard white shell, in the sand.

The Muggar or Marsh- Crocodile (C. palustris) of India has the
snout very short and broad. Crocodilus niloticus is the common
African species and the Indian C. porosus is notable for its size,
attaining a length of 20 feet, and for its habits, as it frequents
estuaries and may be met with out at sea.

Alligators and Caimans differ from Crocodiles in that the
fourth lower tooth is received into a pit in the upper jaw. Alli-
gators inhabit swamps ; there are two species, Alligator mississip-
piensis and A. sinensis, the former North American, the latter
Chinese. The American Alligator constructs a large nest on the
bank, scraping together twigs, leaves, and earth to form a mound
about 3 feet high, in which about 30 eggs are laid in layers.

The Caimans of Central and South America differ from the
Alligators in having a shield of bony plates in the skin of the
under-side of the body ; a fine specimen of the Common Caiman
(Caiman sclerops) is exhibited.

The Gharial (Gavialis gangeticus) of India, and the False
Gharial (Tomistoma schlegelii) of Borneo, have the snout long
and narrow, the two halves of the lower jaw united in a long
symphysis, and the teeth slender and numerous ; they feed
chiefly on fish.

Order 3. CHELONIA.

(Cases 6 to 10.)

The Tortoises, Turtles, and Terrapins constitute this order ;
in them the jaws are toothless and covered with horny beaks,
and the body is typically enclosed in a bony case, the upper half

FIG. 12.

SIDE VIEW OF THE HEAD or THE TIMSA OR NILE CROCODILE
(Crocodilus niloticus).

X Fourth lower tooth.
(Photographed from a specimen in the Museum.)

FIG. 13.

SIDE VIEW OF THE HEAD OF THE N. AMERICAN ALLIGATOR

(Alligator mississippiensis).
(Photographed from a specimen in the Museum.)

22

Guide to Reptiles and Batrachians.

of which is called the carapace and the lower the plastron. The
carapace is supported by the vertebrae and ribs, and in the few
forms in which it has been lost its former presence is shown by
the modification of these elements.

The carapace consists of a number of bony plates arranged in
five series : those of the median series are fused with the neural
spines of the vertebrae below them ; on each side of them are
the costal plates, either supported by the flattened ribs, or, if
they ossify at a stage when the ribs are slender and cartilaginous,

FIG. 14.

Carapace of the Thurgi Batagur (Hardella thurgi). The wavy lines show
the divisions (or sutures) between the bones ; the firm lines indicate those
between the overlying horny shields, c. 1-8, costal bones ; m. 1-11, marginal
bones ; n. 1-8, neural bones ; nu. nuchal bone ; py. pygal bone ; spy. 1, 2.
suprapygal bones. Note that the horny plates do not correspond with the
bony ones.

enclosing the latter ; outside the costals are the marginals. The
bones of the plastron are paired. The horny shields which
usually cover the carapace and plastron have a somewhat similar
arrangement to the bony plates, but do not correspond with
them in size or number.

Chelonians date back to the Triassic and many have been
found fossil in Secondary and early Tertiary strata ; the living

11

0*8

H 2 S

w °

11

as

to

.a

24 Guide to Reptiles and Batrachians.

species number about 300. They may be grouped into two
main divisions : Pleurodira, in which the head is retracted by
a lateral flexure of the neck ; and Cryptodira, in which the head
is retracted by the curving of the neck in a vertical plane.

Pleurodira.

The Pleurodira withdraw the head by a lateral movement of
the neck. They are fresh- water Tortoises, found in South
America, Africa, and Australia.

The Arrau Tortoise of the Amazons (Podocnemis expansa) is
a source of profit to the natives, who collect the soft-shelled eggs,
which are laid in the sand, and extract oil from them ; millions

FIG. 17.

The Matamata Tortoise (Chdys fimbriata) ; reduced.

of eggs are thus destroyed annually. The Matamata (Chelys
fimbriata) of Brazil has the shields of the carapace raised into
knobs ; it feeds on fishes and lies in the water waiting for its
prey, which it is said to attract by the movements of the fringed
appendages which are developed on the skin of the head and
neck.

The Pleurodira include the earliest known Tortoises, the
Triassic Amphichelydidae, and also the large extinct Horned
Tortoises of the family Miolaniidae, found in tertiary deposits of
Australia and Patagonia.

Cryptodira.

This group includes the Chelonians, which bend their neck in
a vertical plane. There are three main divisions : in the first,
containing the typical Tortoises and Turtles, the carapace is
well developed and is bordered by a complete series of marginal
bones connected with the ribs. This division includes the
families Chelydridae, Cinosternidae, Testudinidae, &c., in all of
which the digits are short, as well as the Chelonidae or true
Turtles, in which the anterior limbs are developed into long
paddles.

The Chelydridae include the Snapping Turtle or Snapper

Tortoises and Turtles.

25

(CJielydra serpentina] and the Alligator Turtle (Macroclemmys
temminckii) of North America. These live mostly in the water,
keeping to the bottom, but rising occasionally to breathe ; they
feed on fish and waterfowl and are both fierce and greedy.

The Cinosternidae, or Mud Terrapins, comprise about ten
species of Cinosternum from American rivers.

The Burmese Casked Terrapin (Platy sternum megacephalum) is

FIG. 18.

Temminck's Snapper, or Alligator Turtle (Macroclemmys temmincki) ;

'£ nat. size.
[By permission of Messrs. Macmillan & Co., Ltd.

the only species of the family Platysternidae ; it is aquatic and
has a flattened carapace, a very large head, powerful jaws, and
a long tail.

The large family Testudinidae includes a variety of forms, from
the terrestrial herbivorous Tortoises to the aquatic carnivorous
Batagurs. The typical Land Tortoises (Testudo} are found in
all warm countries except Australasia and some of the Malay
Islands. The carapace is usually dome-shaped and is firmly
united to the plastron, the feet are not webbed, and the tail is
short. The majority of the existing species of Testudo are small

26 Guide to Reptiles and Batrachians.

or of moderate size, like T. graeca of southern Europe, which is
often kept in gardens. Giant Tortoises formerly inhabited most
of the continents, but in recent times they have been found only
on the Galapagos Islands and on certain islands in the Indian
Ocean, namely the Mascarene Islands, the Aldabra group, the
Amirantes and the Seychelles. The Galapagos Tortoises still
survive in diminished numbers, but elsewhere they have been
exterminated by man, South Aldabra alone possessing a small
remnant of its original stock. There are several species in the
Galapagos ; they are vegetable feeders, living on cactuses, leaves
and berries ; the eggs are round and about two inches in diameter.

FIG. 19.

The Abingdon Island Saddle-backed Tortoise (Testudo abingdoni), remarkable
for the thinness of its shell, from the Galapagos group.
(From a specimen in the Museum.)

These Giant Tortoises live to a great age ; a specimen of
Testudo sumeirei, brought from the Seychelles to Mauritius in
1766, was still living in 1902. In several of the species the
carapace is thin and it may be incomplete, as in T. ephippium
and T. abingdoni of the Galapagos. The largest specimen
exhibited belongs to the North Aldabra species T. gigantea.

The reduction of the shell in these large island tortoises was
no doubt related to the absence of carnivorous animals, and it is
of interest to note a still greater reduction in a continental form,
the recently described T. loveridgii from East Africa. This is a
small species, flat in form, with the carapace represented by a
mere network of thin bone. It hides in crevices and under rocks,
its flat flexible carapace enabling it to make its way into such
places and to take advantage of the protection they afford.

The Box -Tortoises (Cistudo) of North America take their
name from the fact that the plastron, which is attached to the
carapace by ligament, is divided by a transverse hinge, so that

Tortoises and Turtles.

27

it can be closed against the carapace after the head, tail, and
limbs have been drawn in.

The Terrapins (Chrysemys) are aquatic American Tortoises
with a flat carapace and webbed feet ; the Painted Terrapin
(C. picta) takes its name from the yellow and red markings on
a dark ground colour. Malacoclemmys terrapin is the well-known
salt-water Edible Terrapin of the United States, where it is
extensively ' farmed ', being fed on shrimps and crabs. The

FIG. 20.

The Painted Terrapin (Chrysemys picta) ; % nat. size.

[By permission of Messrs. Macmillan & Co., Ltd.

Pond-Tortoises (Emys) include one European and one North
American species ; they feed on fishes, worms, &c., and bury
themselves in the mud during the winter. Kachuga, Batagur, &c.,
are aquatic tortoises from India and S.E. Asia. The carapace
and plastron are connected by strong bony buttresses, which
project inwards as vertical partitions ; an example of Batagur
picta exhibited has been prepared to show this structure.

The Chelonidae are the true Turtles, with paddle-shaped limbs.
They are marine, but the females come ashore on sandy coasts to
lay their eggs. The edible Green Turtle (Chelone my das) attains
-a length of 4 feet ; it is found in all warm seas and feeds on sea-

Fin. 21.

SKELETON or LUTH OB LEATHERY TURTLE (Dermochelys coriacea).
To show complete separation of ' shell ' from the vertebrae and ribs.

FIG. 22.

SKELETON OF GREEN TURTLE (Chelone mydaa)

To show union of carapace with vertebrae and ribs.

(From specimens in the Museum.)

Tortoises and Turtles.

29

weeds. The Hawksbill Turtle (C. imbricata) is so called from its
hooked beak ; it is carnivorous ; its horny shields are the chief
source of commercial ' tortoise-shell '. The Loggerhead (Thalas-
sochelys caretta) is a large carnivorous species of no commercial
importance.

We now pass to the second division of the Cryptodira, which
has only one living representative, the Luth or Leathery Turtle

FIG. 23.

Young Hawksbill Turtles (Chelone imbricata) ; % nat. size.

[By permission of Messrs. Macmillan <fc Co., Ltd.

(Dermochelys coriacea), which has neither bony carapace nor
horny shields, but a thick leathery skin containing a mosaic of
small polygonal bony plates; the limbs are paddle-shaped.

The Leathery Turtle is marine and carnivorous, inhabiting all
tropical seas, and laying its eggs on sandy shores. It is the
largest existing Chelonian, reaching a length of nearly seven feet.

The following explanation has been given of the remarkable
structure of Dermochelys. The original Chelonians were terres-
trial and acquired a hard bony carapace as a protection against
attacks ; in some that took to the sea and became pelagic, the
carapace, which was no longer useful, became vestigial (Archelon

30

Guide to Reptiles and Batrachians.

Protostega, &c., of the Upper Cretaceous) ; these resorted to the
coasts to lay their eggs and gave rise to a shore-living form,
which developed a new protective armour of strong polygonal
sculptured bony plates (Cosmochelys of the Lower or Middle
Eocene) ; from such a shore-living form arose Dermochelys, again
pelagic, with the bony armour reduced to small thin smooth
plates embedded in the skin. It is of great interest to note that
this evolutionary sketch was written before the discovery of
Cosmochelys, the most important link in the chain.

FIG. 24.

H28JD ur/m/y

Luth or Leathery Turtle (Dermochelys coriacea) ; young specimens-; lower

and upper view.
[By permission of Messrs. Macmillan 6s Co., Ltd.

The third division of the Cryptodira includes the Soft-shelled
Tortoises (Trionychidae), characterized by the flat, rounded or
oval carapace which does not cover the back completely, the ribs
extending outwards beyond the costal plates and the marginals
being absent ; there are no horny shields and the bones of the
carapace are sculptured externally ; the toes are webbed. The
Trionychidae are carnivorous and aquatic, inhabiting North
America, Africa, and Asia. It has been observed that in the same
species of Trionyx there may be individuals with the horny
sheaths of the jaws narrow and sharp-edged, and others in which
they are broad and flat, the difference being presumably related

Tortoises and Turtles

31

to feeding habits, those with sharp jaws catching fish and the
others crushing shells. Many species of this family have curious
eye-like spots on the back ; the larger kinds may be highly

dangerous to bathers.

FIG. 25.

Young American Soft Tortoises (T'rionyx ferox).
[By permission of Messrs. Macmillan

Co., Ltd.

Order 4. SQUAMATA.

This order contains the Lizards and Snakes, which are charac-
terized by having the quadrate bone movably attached to the
skull and by the presence of not more than one horizontal bony
arch on each side of the temporal region of the skull. The teeth
are welded to the jaws. The majority of living Reptiles belong
to this order, more than 6,000 species having been described,
nearly equally divided between the Lizards and Snakes. There
are two sub-orders, Lacertilia and Ophidia.

32 Guide to Reptiles and Batrachians.

Sub-order 1. Lacertilia.

(Cases 18 to 20.)

In the Lacertilia, or Lizards, the two halves of the lower jaw
are firmly united by suture. There are two main divisions, the
first, the Lacertilia Vera, including the true Lizards, which have
a flat tongue, and the second, Rhiptoglossa, comprising the
Chamaeleons, in which the very long and extremely protractile
tongue is cylindrical, club-shaped at the end.

Division 1. Lacertilia Vera.

The true Lizards are grouped into about 20 families, one of the
characters of most importance in classification being the structure
of the tongue, which may be short or long, entire or bifid at one
or both ends, and either smooth, villose (covered with conical
papillae) or scaly (covered with flat overlapping papillae, which
may unite to form oblique folds). The presence or absence of
4 osteoderms ', little bony plates beneath the scales of the body,
is also of use in classification. In the more typical Lizards each
orbit is surrounded by bone, and from it a bony bar or ' temporal
arch ' runs backwards ; but the orbit may be open behind and
the temporal arch may be absent, these conditions being used
in defining the families.

Most Lizards are terrestrial or arboreal and have well-developed
five -toed limbs, but some are snakelike in form and are limbless,
and there are some degraded burrowing forms which are also
nearly or quite scaleless and look like worms. Some Lizards are
herbivorous, but the majority are carnivorous, the smaller kinds
feeding on insects, worms, &c., and the larger on other animals.
As a rule Lizards lay eggs, but a considerable number are
viviparous.

The Geckonidae, or Geckos, take their name from the fact that
many species utter sounds such as yecko, chucko, &c. They are
Lizards with a smooth or villose tongue, which is slightly notched
in front, with the orbits open behind, without temporal arches,
and with biconcave vertebrae. This is a large and widely
distributed family, Geckos occurring in all tropical and sub-
tropical countries, even on oceanic islands. Some species live
in deserts, sometimes burrowing in the sand ; others are arboreal,
and others live on rocks ; some kinds have acquired the habit
of living inside or outside houses, and it has been observed that
in a house one species may inhabit the cellars, another the roof,
and a third crevices in the walls. The arboreal and rock-climbing
species have the toes expanded and provided on the under side
with transverse lamellae, forming adhesive pads, which are so
effective that Geckos in houses may be seen walking upside down

Lizards and Snakes.

33

on the ceiling. In most Geckos the tail is very brittle, and when
it is broken off a new one is quickly reproduced. The majority
of the species are nocturnal, concealing themselves in the day-
time under stones or under the bark of trees, and at night coming
out of their hiding-places in quest of insects.

Of the species exhibited Tarentola mauritanica is the Common
Gecko of Southern Europe, Ur opiates fimbriatus of Madagascar

FIG. 26.

A, Turkish Gecko (Hemidactylus turcicus), and B, Common Gecko (Tarentola

mauritanica).
[By permission of Messrs. Macmillan & Co., Ltd.

is remarkable for its resemblance to the bark of the trees on
which it is found, and Ptychozoon homocephalum of the Malay
countries has the body bordered by expansions of the skin, which
act as parachutes.

The Eublepharidae is a small family which is distinguished
from the Geckonidae only by having the vertebrae procoelous
(concave in front and convex behind), as in all other Lizards
except the Geckos.

The Pygopodidae of Australia appear to be related to the
Geckos, but are snake-like in form, without fore-limbs and with

FIG. 27.

A.

MALAGASY BARK-GECKOS ( Uroplates fitribrialus).
(From specimens in the Museum.)

Lizards and Snakes.

35
Ex-

the hind-limbs visible externally as a pair of scaly flaps,
amples of Pygopus and Lialis are exhibited.

The Zonuridae of Africa and Madagascar have the tongue
short, villose, scarcely protractile, entire or feebly notched ; the
orbit is surrounded by bone and the temporal arch is present, the
space between it and the skull being roofed over by dermal bone ;
osteoderms are present in Zonurus, the principal genus, in which
the tail is covered with rings of scales ending in sharp spikes.

FIG. 28.

Iguana (Iguana tuberculata).
FIG. 29.

Spiny Iguana, or Calif ornian Toad (PJirynosoma

The Iguanidae differ from the Zonuridae in that the space
between the temporal arch and the skull has no bony roof ;
osteoderms are absent. This is a large and varied family, mainly
American, but with representatives in Madagascar and Fiji.
Iguana tuberculata of tropical America is a large herbivorous
arboreal lizard, with a crest of spines along the back ; it grows
to a length of six feet ; it is edible and is highly esteemed as food.
Basiliscus is noteworthy for the high fin-like crest on the back
of the male, and Polychrus for its chamaeleon-like power of
changing its colour. Phrynosoma cornutum of California, which
lives in dry and sandy places, has the body covered with spines.
Amblyrhynchus cristatus of the Galapagos spends much of its

c 2

36 Guide to Reptiles and Batrachians.

time in the sea and feeds on sea- weed. More than a hundred
species of Anolis have been described ; these are arboreal and
insectivorous lizards, with adhesive pads on the digits.

The Agamidae of Africa, Southern Asia, and Australia are the
old-world representatives of the Iguanidae, from which they differ
in the ' acrodont ' dentition, i. e. the teeth are attached to the
summits of the jaws, whereas in the Iguanidae and most other
Lizards the dentition is pleurodont, i. e. the teeth are attached
on the inner side of the jaws. In the Agamidae the teeth may
usually be divided into three kinds, incisors, canines, and molars.

FIG. 30.

Right half of the Lower Jaw of a Stellion Lizard (a), to exhibit the acrodont
dentition, and of an Iguana (b), to show the pleurodont type of dentition.

Uromastix is found in the desert regions of Africa and Asia ;
the short tail is covered with large spiny scales and the strong
curved claws are used for digging burrows in the sand ; it
feeds on fruits and herbs. Moloch, of the Australian deserts,
is an extraordinary type, with spines on the head, body and
tail. Another interesting Australian form is the Frilled Lizard^
Chlamydosaurus kingi, which, if chased, runs away on its hind-
legs, with the frill round its throat folded up, but when it is likely
to be overtaken will stand and try to frighten away its enemy by
spreading the frill and opening the mouth, which is red inside.
In the Flying Dragons (Draco) of India and Malaysia the long
ribs extend outwards beyond the body to support the mem-
branous ' wings ', by means of which they sail from tree to tree.

In all the Lizards so far considered the smooth or villose
tongue is entire or slightly notched in front ; the next two
families are characterized by a tongue which is mainly villose,
but has a smooth anterior bifid protractile portion. The Helo-
dermatidae include the genus Heloderma, the only poisonous
Lizard known ; its fang-like teeth are grooved for the passage of
the poison, which is secreted by glands inside the mouth. The

FIG. 31

Spiny-tailed Lizards ( Uromastix acanthurus) • J nat. size.

[By permission of Messrs. Macmillan <£? Co., Ltd.

FIG. 32.

Australian Frilled Lizard (Chlamydosaurus kingi), with the frill expanded in
the ' terrifying ' attitude.

FIG. 33.

Australian Moloch Lizard (Moloch horridus).
FIG. 34.

A Flying Lizard, or ' Flying Dragon ' (Draco taeniopterus}.

Lizards and Snakes.

39

Gila Monster (H. suspectum) of Arizona and New Mexico is
a stout, thick-tailed lizard, with the skin spotted or banded with
orange or yellow on a dark ground, a common type of ' warning '
coloration. The rare Lanthanotus of Borneo is allied to Helo-
derma, but its teeth are not grooved.

The Anniellidae of California contain but a single genus,
Anniella, snake -shaped limbless lizards.

The Anguidae are characterized by the structure of the tongue,
which is divided into a thick villose posterior portion and a thin

FIG. 35.

The Gila Monster (Heloderma suspectum) ; ± nat. size.

[By permission of Messrs. Macmillan & Co., Ltd.

scaly forked anterior portion which can be extended and retracted.
Osteoderms are present on the body, and the space between the
temporal arch and the skull is roofed over by dermal bone. These
are terrestrial and carnivorous lizards, mostly American, but
with representatives in Europe and Asia ; their long tail is
brittle and readily replaced. The genera show a transition from
Diploglossus, with the limbs well-developed and pentedactyle to
Anguis, which has no trace of limbs ; the Slow-worm (Anguis
fragilis) is a British species.

The Xenosauridae, with a single species from Mexico, differ
from the Anguidae in having no osteoderms on the body or head.

40 Guide to Reptiles and Batrachians.

The Varanidae or ' Monitors ' are characterized by the long,
smooth protractile tongue, which is forked at the end ; all the
species are included in the genus Varanus, which occurs
in Africa, Southern Asia, and Australia ; some of them reach
a length of seven feet, but still larger kinds are found fossil.
The Monitors are mainly terrestrial, but most of them are quite
at home in the water, which perhaps accounts for their wide dis-
tribution ; all are carnivorous and many are fond of birds' eggs.

We now pass from the Lizards with the tongue wholly or
mainly smooth or villose to those in which it is covered with
scale-like papillae. Of these the most generalized family is the
Scincidae, in which the tongue is feebly notched in front, the

FIG. 36.

The Slow-Worm (Anguis fragilis) ; \ nat. size.

[By permission of Messrs. Macmillan & Co., Ltd.

body is protected by bony plates underlying the scales, and the
space between the temporal arch and the skull is roofed over by
dermal bones. The Skinks are cosmopolitan, being especially
abundant in Africa, Malaysia, and Australia ; like the Geckos
they are found in all the islands of the Pacific Ocean. They are
carnivorous and terrestrial, showing a preference for dry and
sandy regions ; the species of several genera may be arranged
in series showing the gradual reduction and ultimate loss of the
limbs connected with their burrowing habits ; this is illustrated
by a series of specimens of Chalcides. Trachysaurus rugosus of
Australia is remarkable for its large rough scales and short
tail. ScincuB officinalis is the common Skink of the deserts from
the Sahara to Sindh. Lygosoma is widely distributed and has
nearly 200 species. The Anelytropidae of Africa and Mexico are

Lizards and Snakes.

41

FIG. 37.

worm-like limbless burrowing forms closely related to the
Scincidae, differing in having the
orbits open behind and in having
no temporal arches.

The small American family Xan-
tusiidae differs from the Scincidae
in having no osteoderms.

The Gerrhosauridae of Africa and
Madagascar differ from the Scin-
cidae in the structure of the tongue,
which is bifid behind. The Diba-
midae include Dibamus novae-
guineae, which has a tongue like
that of the Gerrhosauridae, but is
a limbless vermiform burrowing
type.

The Lacertidae are found in
Europe, Asia, and Africa ; the
long scaly tongue is bifid both in
front and behind, the temporal
region of the skull has a bony roof,
but there are no osteoderms on the
body. These Lizards are terrestrial
and insectivorous . Lacerta includes
the Common Lizard (L. vivipara),

Hind-legs of Skinks, to show
the gradual abortion.

a, Chalcides ocellatus.

b, Chalcides mionecton.

c, Chalcides tridactylus.

d, Lygosoma lineo-puncttdatum.

e, Chalcides guentheri.

in which the young burst the eggs just before or just after they
are laid, the Sand Lizard (L. agilis), the Green Lizard (L. viridis),
the Wall Lizard (L. muralis), and the Eyed Lizard (L. ocellata) ;
these are European species, the first two of which occur in
England.

FIG. 38.

Stump-tailed Skink (Trachysaurus rugosus) ; | nat. size.

[By permission of Messrs, Macmillan & Co., Ltd.

42

Guide to Reptiles and Batrachians.

The Teiidae are American Lizards with a scaly tongue, which
ends in front in two long smooth points. There are no bony
plates in the skin ; the orbit is complete, the temporal arch is
present, and the space between it and the skull is not roofed by
bone. This family includes arboreal, terrestrial, and burrowing
forms, the last being worm-like and limbless. The Great Teju
(Tupinambis teguixin) of South America reaches a length of
three feet ; it is strong and active, living on all kinds of animals.
Dracaena has the lateral teeth very broad and rounded.

The Amphisbaenidae of America and Africa differ from the
Teiidae in having the orbits open behind and the temporal arches

FIG. 39.

The Eyed Lizard (Lacerta ocellata) ; ± nat. size.

[By permission of Messrs. Macmillan & Co., Ltd.

absent. They are worm-like and for the most part limbless ; the
body is covered with soft skin, which forms numerous rings ; the
scales are mere vestiges. These burrowing lizards bore narrow
galleries in the earth and are distinguished from all other limbless
Reptiles by their method of progression, moving either forwards
or backwards in a straight line, by slight vertical undulations
and not by lateral movements. They feed on worms and insects.

Division 2. Rhiptoglossa.

Chamaeleons are distinguished from the true Lizards by a
number of peculiarities. The tongue is cylindrical, club-shaped
at the end, and can be extended to a great length. The limbs
are long and two of the toes are opposed to the other three,
forming a grasping foot. The head is ornamented with crests
or tubercles, the neck is short, the compressed body is covered
with granules, and the tail is long and prehensile. The large eyes
are covered with a thick granular lid pierced by a small central
opening for the pupil.

Lizards and Snakes.

43

These arboreal Reptiles are unique in their slow and deliberate
movements, the mobility and independent action of their eyes,

FIG. 40.

Head of the Common Chamaeleon (Chamaeleon vulgaris), with the
tongue partially protruded.

FIG. 41.

The Common Chamaeleon (Chamaeleon vulgaris) ; f nat. size.

[By permission of Messrs. Macmillan & Co., Ltd.

and the rapid projection of the tongue to a length of several
inches in order to catch the insects on which they feed. They are

44 Guide to Reptiles and Batrachians.

famed for their power of changing the hues of their skin, but this
is shared with many other Lizards.

Nearly all the species inhabit Africa or Madagascar ; one is
Indian, one Arabian, whilst the Common Chamaeleon (C. vulgaris)
is found in Spain and in the countries south and east of the
Mediterranean .

Sub-order 2. Ophidia.
(Cases 11-15.)

Snakes differ from Lizards in having the two halves of the
lower jaw united by ligament. The body is elongate and the
limbs are vestigial or absent, but these are characters shared
with many Lizards.

The essential feature of a typical Snake is the apparatus for
distending the mouth ; the lower jaw bones are long and are
connected together in front by an elastic ligament, whilst behind
they are articulated with the long, movable quadrate bones,
which are attached to the long and backwardly directed squa-
mosals ; the long pterygoid bones are connected with the maxil-
laries in front and are loosely attached to the quadrates behind ;
the teeth are pointed and curved backwards. This apparatus
enables a snake to swallow a prey several times its own diameter.

The first family is that of the Boidae, in which the mouth has
the structure just described, the praefrontal and nasal bones are
in contact, and vestiges of the pelvis and hind-limbs are present,
the latter appearing externally as a pair of claws. None of the
members of this family is poisonous ; the larger kinds inhabit
forests and feed by choice on warm-blooded animals, which they
crush in their -coils before swallowing them. The Pythons are
found in Africa, Southern Asia, and Australia. Python reticulatus
is the common Malay species ; it attains a length of 30 feet.
The Australian Carpet-Snake (P. spilotes) has beautiful markings.
Boa constrictor is a well-known South American Snake. The
huge Anaconda (Eunectes murinus) of tropical America is both
arboreal and aquatic ; it is said to grow to a length of more
than 30 feet.

The next five families include snakes of burrowing habits,
which agree with the Boidae in having the praefrontal and nasal
bones in contact, but differ in the smaller size of the mouth, in
relation to a diet of insects, worms, &c.

In the Xenopeltidae (Xenopeltis unicolor of India and Malaysia)
the squamosal is short and does not carry back the quadrate
behind the skull. In the Ilysiidae the squamosal is very small,
but in other characters of the skeleton they agree with the
Boidae, even to having vestiges of the pelvis and hind-limbs, the
latter appearing externally as a pair of claws. The head is small

Lizards and Snakes.

45

and the tail is very short and blunt. The Coral-Snake (Ilysia
scytale) of South America is red with black rings ; the few other
members of the family inhabit Ceylon and Malaysia ; Cylindrophis
rufus is exhibited.

FIG. 42.

-pm>

.--d,

B. C.

Skull of the Grass Snake (Tropidonotus natrix).

From the left side (A), above (B), and below (C).

an. Angular.
ar. Articular.
bo. Basioccipital.
bs. Basisphenoid.
ca. Oolumella auris.
d. Dentary.
eo. Exoccipital.
epg. Ectopterygoid.

/. Frontal.
in. Maxillary.
n. Nasal.
p. Parietal.
pi. Palatine.
pm. Praemaxillary.
prf. Praefrontal.

pro. Prootic.

pg. Pterygoid.
ptf. Postfrontal.

q. Quadrate.

so. Supraoccipital.
ste. Squamosal.
v. Vomer.

The Uropeltidae are small burrowing snakes of India and
Ceylon ; they differ from the Ilysiidae in having the small
quadrates directly attached to the skull, the squamosals having

FIG. 43.

BONES
of the
CLAW.

A. — PART or THE FLATTENED SKIN or AN AFRICAN PYTHON (Python sebae).
Showing Claws representing Hind-Limbs, together with their supporting bones.

B. — COMPLETE BONES OF THE HINDER LIMB-GIRDLE OF ANOTHER

SPECIMEN.
VESTIGIAL LIMBS OF PYTHONS.

Tortoises and Turtles. 47

been lost ; the pterygoids do not reach the quadrates and there
are no traces of pelvis or hind limbs : the tail ends in a shield.

The Glauconiidae and Typhlopidae form a group apart, retain-
ing vestiges of the pelvis, but in other respects showing the most
complete adaptation to a burrowing life ; the quadrate bones are
rather long and slender and are directed obliquely forwards ;
behind they are attached to the skull directly, there being no
squamosals. The body is covered with uniform cycloid scales,
the snout projects beyond the small mouth and the minute eyes
lie under the shields of the head. In the Typhlopidae the lower

FIG. 44.

Australian Carpet- Snake (Python spilotes).

[By permission of Messrs. Macmillan cfc Co., Ltd.

jaw is toothless, and the teeth in the upper jaw form a transverse
series ; in the Glauconiidae teeth are present in the lower jaw
only. Typhlops is a large genus, found in all warm countries ;
Glaucoma inhabits America, Africa, and S.W. Asia.

The large family Colubridae includes the great majority of
living Snakes, in fact all the normal or typical Snakes which are
neither Boidae nor Viperidae. The mouth has the structure
described above as typical, i.e. the pterygoids reach the quadrates,
which are attached to the long backwardly directed squamosals ;
the features which distinguish this family from the Boidae are
that the praefrontals are not in contact with the nasals and there
are no traces of pelvis or hind-limbs.

The Colubridae have been divided into eight sub -families, not
all of which are natural ; these have been grouped into three
series, Aglypha, with the teeth solid or ungrooved, Opisthoglypha,
with the hinder upper teeth grooved, and Proteroglypha, with the
front upper teeth grooved or perforated. The Aglypha are

48

Guide to Reptiles and Batrachians.

mostly harmless, the Opisthoglypha venomous but not dangerous ,
the Proteroglypha deadly.

The principal sub -family of the Aglypha is the Colubrinae,
which includes the Grass Snake (Tropidonotus natrix) and the
Smooth Snake (Coronella austriaca), both found in Britain ; these
harmless snakes are distinguished externally from the venomous
Adder (Vipera berus) by the large shields on the head (fig. 45).

FIG. 45.

FIG. 46.

Heads of the Smooth Snake (Coronella austriaca), A,
and the Grass Snake (Tropidonotus natrix), B.

Heads of the three British Snakes.

Head of the Viper
(Vipera berus).

The Black Snake (Zamenis constrictor) of North America is
slender in form and is very active on land as well as in climbing
trees ; it feeds on mice, frogs, birds, &c. Coluber quadrilineatus
is a handsome European species. Dendrophis and Liophis are
Tree-snakes.

Dasypeltis of Africa and Elachistodon of India are interesting ;
they have no teeth in the front of the jaws, but their most
remarkable peculiarity is that the lower spines of the neck
vertebrae pierce the gullet, forming a series of tooth -like knobs,
which are used for crushing the eggs on which they feed.

The sub-family Elapinae includes terrestrial snakes with a cylin-
drical tail ; the front upper teeth are grooved or perforated for
the passage of the poisonous secretion ; all the venomous snakes
of Australia belong to this group. The Cobras (Naia) of Africa
and Southern Asia are characterized by the power of expanding
the neck to form a hood by an outward and forward movement
of the ribs (fig. 48). These snakes are very deadly, as are the
Kraits (Bungarus) of India, which have no hood. Elaps is an

Lizards and Snakes.

49

American genus with several species, most of which are banded
with red and black.

The Hydrophiinae are Sea-snakes ; they differ from the
Elapines in having the tail compressed for the purpose of swim-
ming. They inhabit the Indian and Pacific Oceans, and as a rule
are not found far from land ; they feed on fish and are viviparous.
Indian fishermen are sometimes bitten by these snakes, and the
bite may prove fatal.

FIG. 47.

African Egg-eating Snake (Dasypdtis scabra) ; £ nat. size.

[By permission of Messrs. Macmillan 60 Co., Ltd.

The Amblycephalidae of South America and Malaysia stand
in much the same relation to the Colubrines that the Ilysiidae do
to the Boidae.

The Viperidae (Vipers, Rattlesnakes, &c.) differ from the
Colubridae in having the maxillaries short, each bearing only
a single poison-fang, which is perforated for the passage of the
poisonous secretion. The true Vipers have solid maxillaries and
no pit between the eye and the nose ; they are found in Europe,
Asia, and Africa. Vipera berus is the Common Viper, or Adder, of
Europe ; its bite is generally not fatal to man. Bitis arietans is
the Puff Adder of Africa, which reaches a length of 4 or 5 feet ;
when disturbed it raises the head, inflates the body, and hisses
loudly. The Horned Puff Adder (B. nasicornis) has two or three
horn-like projections on the snout, whilst the Horned Viper

FIG. 48.

Heads of Indian Cobras (Naia iripudians) ; \ nat. size.

FIG. 49.

The Puff-Adder (Bitis arietans) ; J nat. size.

\By permission of Messrs. Macmillan & Co., Ltd.

Lizards and Snakes. 51

(Cerastes cornutus) has one above each eye. The last-named
species inhabits the desert and has a dull uniform coloration,
whereas most Vipers possess handsome markings.

The Pit-Vipers of America and Asia have a sensory pit on each
side between the eye and the nose, lodged in the hollowed out
maxillary bones. This group includes the American Rattle-
snakes (Crotalus), which have at the end of the tail a rattle made
up of a number of bells which fit into one another ; these ' bells '
are really the successive horny sheaths of the tip of the tail,
a new one being added at each moult, when the rest of the skin is
cast off. Other American species are the Water Viper (Ancis-
trodon piscivorus), which feeds chiefly on fishes, and the deadly
Fer-de-lance (Lachesis lanceolatus). Lachesis is also represented
in Asia, a well-known species being the Indian Green Viper
(L. gramineus), which lives in trees.

53

INDEX

Adder, 48, 49
Adder, Puff, 49, 50
Aelurognathus, 17
Agamidae, 36
Aglossa, 14
Aglypha, 47, 48
Alligator Turtle, 25
Alligators, 20
Alytes, 14

Amblycephalidae, 49
Amblyrhynchus, 35
Amblystoma, 9
Amphibia, 7
Amphichelydidae, 24
Amphisbaenidae, 42
Amphiuma, 11
Amphiumidae, 11
Anaconda, 44
Ancistrodon, 51
Anelytropidae, 41
Anguidae, 39
Anguis, 39, 40
Anniella, 39
Anolis, 36
Anomodontia, 17
Anura, 12
Apoda, 12
Archelon, 30
Arcifera, 14
Arrau Tortoise, 24
Axolotl, 9

Basiliscus, 35

Batagur, 27

Batrachians, 7

„ Limbless, 11

Tailed, 8
Tailless, 12

Bitis, 49

Black Snake, 48

Boa, 44

Boidae, 44

Bombinator, 14

Box-Tortoise, 26

JBufo, 14

Bufonidae, 14

Bull-Frog, 16

Bungarus, 48

Caiman, 20
Californian Toad, 35

Carpet-Snake, 44
Casked Terrapin, 25
Ceratobatrachus, 16
Ceratophrys, 14
Chalcides, 40, 41
Chamaeleon, 42
Chelone, 27
Chelonia, 20
Chelonidae, 27
Chelydra, 25
Chelys, 24

Chlamydosaurus, 36, 37
Chrysemys, 27
Cinosternum, 25
Cistudo, 26
Clawed Toad, 14
Cobra, 48, 50
Coecilia, 12
Coecilians, 12
£oZw&er, 48
Colubridae, 47
Colubrinae, 48
Common Frog, 16

,, Lizard, 41

„ Toad, 14
Coral-Snake, 45
Coronella, 48
Cosmochelys, 30
Cotylosauria, 17
Crocodile, 20

Marsh, 20
Crocodilia, 19
Crocodilus, 20
Crotalus, 51
Cryptobranchus, 11
Cryptodira, 24
Cylindrophis, 45
Cystignathidae, 14

Dasypeltis, 48
Dendrobatidae, 16
Dendrophis, 48
Dermochelys, 28, 29, 30
Desmognathus, 10
Dibamidae, 41
Dibamus, 41
Dinosauria, 17
Diplodocus, 17
Diploglossus, 39
Discoglossidae, 14

54

Index

Dracaena, 42
Draco, 36, 38
Dragon, Flying, 36, 38

Edible Frog, 16

„ Terrapin, 27
Egg-eating Snake, 48, 49
Elachistodon, 48
Elapinae, 48
Elaps, 48
Emys, 27

Engystomatidae, 16
Eublepharidae, 33
Eunectes, 44
Eyed Lizard, 41, 42

False Gharial, 20
Fer-de-lance, 51
Fire-bellied Toad, 14
Firmisternia, 16
Flying Dragon, 36, 38
„ Lizard, 36, 38
Frilled Lizard, 36, 37
Frog, Bull, 16

,, Common, 16

„ Edible, 16

„ Horned, 16

„ Pouched, 15, 16
Frogs, 12

Gamalis, 20
Geckonidae, 32
Geckos, 32
Gerrhosauridae, 41
Gharial, 20

False, 20
Giant Salamander, 11

„ Tortoises, 26
Gila Monster, 39
Glauconia, 47
Glauconiidae, 47
Grass Snake, 48
Great Teju, 42
Green Lizard, 41

Turtle, 27. 28

„ Viper, 51

Hawksbill Turtle, 29

Hellbender, 11

Heloderma, 36, 39

Hemidactyliis, 33

Horned Frog, 16

„ Puff Adder, 49
„ Toad, 14, 15
„ Viper, 49

Hyla, 14

Hylidae, 14

Hymenochirus, 14

Ichthyophis, 12
Ichthyosauria, 19
Iguana, 35

„ Spiny, 35
Iguanidae, 35
Iguanodon, 17
Ilysia, 45
Ilysiidae, 44

Kachuga, 27
Krait, 48

Lacerta, 41
Lacertidae, 41
Lacertilia, 32
Lacertilia Vera, 32
Lachesis, 51
Lanthanotus, 39
Leathery Turtle, 28, 29, 30
Leptodactylus, 14
Lialis, 35

Limbless Batrachians, 11
Liodon, 19
Liopelma, 14
Liophis, 48
Lizard, Common, 41

Eyed, 41, 42

Flying, 36, 38

Frilled, 36, 37

Green, 41

Sand, 41

Spiny-tailed, 36, 37

Wall, 41
Lizards, 32

Loggerhead Turtle, 29
Luth, 28, 29, 30
Lygosoma, 41

Macrodemmys, 25
Marsh-Crocodile, 20
Matamata, 24
Megalobatrachus, 11
Miolaniidae, 24
Molge, 8
Moloch, 36, 38
Monitors, 40
Monster, Gila, 39
Mosasauria, 19
Muggar, 20

Naia, 48, 50
Natterjack Toad, 14
Necturus, 11
Newts, 8
Nototrema, 15, 16

Olm, 11
Ophidia, 44
Opisthoglypha, 47

Index

55

Painted Terrapin, 27
Pelobates, 13, 14
Pelobatidae, 14
Phrynosoma, 35
Pipa, 13, 14
Pit- Vipers. 51
Platy sternum, 25
Plesiosauria, 19
Pleth-odon, 10
Pleurodira, 24
Podocnemis, 24
Polychrus, 35
Pond-Tortoise, 27
Pouched Frog, 15, 16
Proteidae, 11
Proterogiypha, 47
Proteus, 11
Protostega, 30
Pseudis, 13
Pt&ranodon, 19
PterodactyK 19
Ptychozoon, 33
Puff Adder, 49, 50

Horned, 49
Pygopodidae, 33
Pygopus, 35
Python, 44

16

Ranidae, 16
Rattlesnake, 51
Reptiles, 17
Rhacophorus, 16
Rhamphorhynchus, 17
Rhiptoglossa. 42
Rhynchocephalia, 19

Salamander. Giant, 11

Salamanders, 9

Salamandra, 9

Salamandridae, 8

Sand Lizard, 41

Scincidae, 40

Scincus, 40

Sea-snakes, 49

Siphonops, 12

Sirenidae, 11

Skink, Stump- tailed, 40, 41

Skinks, 40

Slow- worm, 39, 40

Smooth Snake, 48

Snake, Black, 48

Carpet, 44

Coral, 45

Egg-eating, 48, 49

Grass, 48

Smooth, 48

Snakes, 44

Sea, 49
Snapper, 24
Snapping Turtle, 24
Soft-shelled Tortoises, 30
Spade-footed Toad, 14
Spelerpes, 10
Sphenodon, 18, 19
Spiny Iguana, 35
Spiny-tailed Lizard, 36, 37
Squamata, 37
Stegocephala, 7
Stump-tailed Skink, 40, 41
Surinam Toad, 13, 14

Tailed Batrachians, 8
Tailless Batrachians, 12
Tarentola, 33
Teiidae, 42
Teju, Great, 42
Terrapin, Casked, 25
Edible, 27
Painted, 27
Terrapins, 20, 27
Testudinidae, 25
Testudo, 25
ThalassocMys, 29
Toad, Californian, 35
Clawed, 14
Common, 14
Fire-bellied, 14
Horned, 14, 15
Natterjack, 14
Spade-footed, 14
Surinam, 13, 14
Toads, 12
Tomistoma, 20
Tortoise, Arrau, 24
Box-, 26
Pond-, 27
Soft-shelled, 30
Tortoises. 20, 24

Giant, 26
Tortoise-shell, 29
Trachysaurus, 40, 41
Triceratops, 17
Trionychidae, 30
Trionyx, 30
Triton, 8
Tropidonotus, 48
Tuatera, 18, 19
Tupinambis, 42
Turtle, Alligator, 25
Green, 27, 28
Hawksbill, 29
Leathery, 28, 29, 30
Loggerhead, 29
Snapping, 24

Turtles, 20, 27
Typhlomolge, 11
Typhlops, 47
Typhlopidae, 47

Uraeotyphlus, 12
Urodela, 8
Uromastix, 36, 37
Uropeltidae, 45
Uroplates, 33, 34

Varanidae, 40
Varanus, 40
Viper, 48, 49
„ Green, 51
Horned, 49

Index

Viper, Water, 51
Viperidae. 49
Vipers, Pit, 51

Wall Lizard, 41
Water Viper, 51

Xantusiidae, 41
Xenopeltidae, 44
Xenopeltis, 44
Xenopus, 14
Xenosauridae, 39

Zamenis, 48
Zonuridae, 35
Zonurus, 35

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