British Museum (Natural History). Dept. of Zoology.

Guide to the reptiles and batrachians exhibited in the Department of zoology of the British museum (Natural history).. online

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Online LibraryBritish Museum (Natural History). Dept. of ZoologyGuide to the reptiles and batrachians exhibited in the Department of zoology of the British museum (Natural history).. → online text (page 1 of 3)
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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.


Keeper of Zoology.

March 1922.




BATRACHIANS . ... . . . . 7


APODA (CoECiLiANs) . . . . . .11

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

REPTILES . . . . . . . 17










(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.


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.


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


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 w r ater,
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

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.


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


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

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


Frogs and Toads.


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.


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 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

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.


(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.


(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

1 3

Online LibraryBritish Museum (Natural History). Dept. of ZoologyGuide to the reptiles and batrachians exhibited in the Department of zoology of the British museum (Natural history).. → online text (page 1 of 3)