A GUIDE '^ "^'^''"^r-

0, 0^^

TO THE ^ ;

TO THE V. ,

ZOOLOGICAL COLLECTIONS

EXHIBITED m THE

INVERTEBRATE GALLERY

OF THE

INDIAN MUSEUM.

CALCUTTA :
PRINTED BY ORDER OF THE TRUSTEES OF THE INDIAN MUSEUM.

1894.

Price Ten annas.

31

A GUIDE

TO THE

ZOOLOGICAL COLLECTIONS

^hc trustees

OF

THE INDIAN MUSEUM.

CALCUTTA :
PRINTED BY ORDER OF THE TRUSTEES OF THE INDIAN MUSEUM,

1894.

Price Ten annas.

CALCUTTA :

GOVERNMENT OF INDIA CENTRAL PRINTING OFFICE,

8, HASTINGS STREET,

<

PREFACE.

♦

'' I ^HIS Guide is issued with the main object of
assisting those who may have occasion to
study in detail the collections contained in the
Invertebrate Gallery, but it is believed that it will
be of equal service to the casual visitor.

The exhibited collections of Sponges and Corals,
of Echinodermata, of Crustacea, and of Mollusca,
may be regarded as at the least thoroughly re-
presentative of the Seas of India both in the shallows
and in the depths, as far as the depths are known at
present ; but owing in the one case to want of space,
and in the other case to the incompleteness of our
present knowledge, the respective collections of the
air-breathing Arthropoda of the Indian region (ex-
cepting only the Lepidoptera, and the Mantidae
among the Orthoptera) and of most of the groups
of Worms of the Indian region, are intended only to
illustrate important generic types.

A. ALCOCK, Surg eon- Captain,

Superintenderit of the Indian Museum,

Indian Museum, Calcutta;
2ist May iSg^.

A GUIDE

TO THE

ZOOLOGICAL COLLECTIONS

EXHIBITED IN THE

INVERTEBRATE GALLERY
OF THE INDIAN MUSEUM.

INTRODUCTORY.

THE matter of which the terrestrial system consists is
either inorganic (mineral matter) or organic (living
matter).

[We also include as organic matter all such dead
substances as are or have been formed in Nature only by
the agency of living plants and animals — such as starches,
sugars, fats, albumens, alkaloids, and such as coal and
other fossils].

Living organic matter differs broadly from the in-
organic matter of the Mineral kingdom in being, on the
one hand, liable to rapid dissolution and decay, but in being
able, on the other hand, to spontaneously renew and in-
crease itself out of the various inanimate substances with
which it is brought into relation. The cycles of compli-
cated physico-chemical changes that occur in the course
of this constant decay and renewal constitute Life.

Living bodies are divided into (i) Animals which feel,
and can move spontaneously ; (2) Plants which do not.
Although we have no difficulty in distinguishing a highly
developed animal, e.g,, a vertebrate, from a highly devel-
oped plant, e.g,, a flowering tree, yet when we descend in

A Guide to the Zoolopical Collections in the

the animal kingdom we find many groups of animals, e.g.,
the Sponges, which being devoid of organs of sensation and
beino- devoid of the power of voluntary movement were
for a long time classed as plants, and when we descend to
the lowest foundations of the vegetable kingdom we find
many microscopic plants, which being endowed with the
power of spontaneous motion were at first classed as
animals.

The broad distinction that holds good, in the main,
throughout the two kingdoms is that Plants live upon and
build themselves up out of inorganic substances, while
Animals can only live upon and build themselves up out
of already-made organic substances.

In other words, in the cycle of Nature, Plants are manu-
facturers of organic substances for the consumption of
Animals.

All Animals and Plants are built up of cells.
[The word "cell," as used in biology, means a micros-
copic mass of semi-fluid living-substance or protoplasm
usually containing a denser body known as the nucleus,
and sometimes surrounded by a membrane or wall : the
semi-fluid living jelly or protoplasm of which cells are
made, is an extremely complex chemical compound of
Carbon, Nitrogen, Oxygen, Hydrogen, Sulphur, etc.].

For purposes of classification Animals are divided into
(i) Protozoa^ or animals that consist of a single cell, and
(2) Metasoa, or animals that consist of an aggregate of
cells.

The Metazoa again are sub-divided into (i) Ccelen-
terata, or animals in which the cavity of the body is
formed entirely by the intestine ; and (2) Ccelomata, or
animals in which there is a distinct body-cavity through
which the intestinal tube runs, — like a lamp-chimney
through a lamp-globe.

The Coelomata are further sub-divided into several great
phyla or family unions, namely, (i) the Platyheltninthes
or Flat-worms, of which the common Liver Fluke may
be taken as a type ; (2) the Nemathelminthes or Non-

Invertebrate Gallery of the Indian Museum. 7

segmented Round-worms, of which the common Intestinal
worm may be taken as a type ; (3) the Annelida or
Segmented worms, of which the common Earth-worm may
be taken as a type ; (4) the Arthropoda or Segmented
animals with many-jointed legs, of which the common
Prawn may be taken as a type ; (5) the Echinodermata^
of which the Star-fish may be taken as a type ; (6) the
Mollusca, of which the common Snail may be taken as a
type ; and (7) the Vertebrata, or animals which possess at
some tim.e of their life either a backbone or the element
out of which a backbone is developed, of which the Fish,
the Frog, the Crocodile, the Bird, and the Mammalian
quadruped are types.

The old Lamarckian classification of animals is into
(i) Vertebrata and (2) Invertebrata — the latter including
the Protozoa^ the Ccelenterate Metasoa, and all the Coslo'
mate Metasoa, with the exception of that portion of the
Vertebrate phylum which consists of animals charac-
terized by a well-developed backbone.

PROTOZOA.

[(JDccu^Jging the Southern enb of OTasc I oxx ih.z Wizsiztw siic
of the (ialUrg].

The Protozoa are microscopic animals which consist
of a single cell, in other words of a single minute speck
of protoplasm, usually with a nucleus, sometimes with
several nuclei, but occasionally {Monera) without a
nucleus, and the great majority of them therefore can only
be represented in a Museum collection by enlarged models
and drawings.

Many species, however, are able to secrete protective
shells of chitin or of lime or of flint, or to manufacture
tests by the agglutination of minute grains of sand, and
some of these are large enough to be distinguished by the
naked eye.

8 A Guide to the Zoological Collections in the

Most of the Protozoa are aquatic : the species of one
group — the Gregarinida — live as parasites in the interior
of the cockroach, the earth-worm, and other animals.

In the Museum collection the shell-secreting Protozoa
are well represented — both actual shells and enlarged
models.

There are two great groups of shell-secreting Protozoa
— (i) the Radiolaria, the shells of which consist of flint,
and (2) iViQ, Foraminifera,i\\& shells of which consist either
of agglutinated sand-grains or, more commonly, of chitin
(a flexible horny substance like that which forms the wing-
cases of beetles and the integument of Crustacea and many
other invertebrate animals), impregnated and strengthened
with either carbonate of lime or flint.

Only the Foraminiferal Protozoa will be here described,
as they alone are represented in the collection by actual
specimens visible to the naked eye.

The Foraminifera are aquatic (mostly marine) Pro-
tozoa in which the body is enclosed in a shell which is
usually perforated all over with little holes like a sieve,
whence the name Foramirtifera, but in some cases is
entire with at one end a single opening, or mouth, just
like, for example, a snail-shell. From the little holes in the
shell-wall, or from the mouth of the shell, the living
animal puts forth and draws in again thread-like processes
of its own body-substance, which are known as pseudopodia,
and it is by the continuous motion of these threads of pro-
toplasm, or pseudopodia, that the animals move from place
to place and seize their minute prey.

The great majority of the Foraminifera live in the sea.
At the surface of the great oceans they exist in countless
numbers, and as they die their shells fall to the bottom,
where they form deposits of vast extent known as " Fora-
miniferal ooze," or, form the name of the commonest and
one of the largest of the oceanic species, " Globigerina
ooze." When dry this ooze has all the appearance of com-
mon chalk, and the White Chalk of Geology is in fact

Invertebrate Gallery of the Indian Museum. g

simply Foraminiferal ooze that has been laid down in the
seas of past geological ages, and has since been upheaved
into dry land.

Among the exhibits are to be seen : —

I. — Pelagic and Deep-sea Forominifera : —

(i) A piece of rough dried Glohigerina ooze from the
Bay of Bengal,

(2) Glohioerina ooze from the Laccadive Sea washed

free from impurities, and dried : this specimen
shows the constituent shells as a coarse
powder.

(3) Specimens of Glohigerina bulloides, one of the

commoner "perforate " forms, mounted sepa-
rately.

(4) Specimens of Pulvinulina menardii, another very

common " perforate " form, mounted separate-

All these come from depths of one thousand to two
thousand fathoms.

The imperforate forms are well illustrated by a large
specinien of (5) Horniosina bradyi dredged in the Bay
of Bengal at a depth of 561 fathoms. The shell of
Horniosina consists not of lime, but of chitin strengthened
on the outside by a smooth compact coat of minute grains
of sand, and at one end of the shell is the opening — shown
in the enlarged drawing that accompanies the specimen —
from which the pseudopodia are emitted in a bunch.
II. — Littoral and shallow-water Foraminifera : —
(i) Orbitolites.

(2) Nummulina.

(3) Alveoli na.

(4) Planorbiilina.

III. — The other exhibits in the Protosoa-cdLse are a
series of models of recent and extinct Forami-
nifera much enlarged ; and

IV. — Enlarged drawings of the other types of
Protozoa—vis.^ Monera, Amwba, Thalassicolla

10 A Guide to the Zoological Collections in the

and Sphxrozoum, Chilomonas, Paramcecium,
and Gregarina^ for an account of all of which
the visitor is referred to works on systematic
zoology.
The last exhibit is (V) a specimen of Eozoon canadense
from Canada, presented by Lady Dufferin. Eozoon has
been supposed to be the fossil remains of a gigantic Fora-
minifer, and its interest lies in the fact that, if fossil, it re-
presents, geologically speaking, the most ancient form of
life known to us. It is not generally conceded, however,
that Eozoon represents an organic structure.

METAZOA.

We next come to the Metazoa^ or animals that consist
of a complex of cells.

Among the Protozoa the single simple cell performs,
though imperfectly, all the various functions by which
life is maintained : it receives simple impressions from
without, e.g. of the proximity of food, it is locomotive,
it takes hold of and digests prey, it respires, it circulates
its assimilated nutriment, and it excretes its useless waste, —
and in most of the Protozoa it does all this with any and
every part of its simple unicellular body.

But when a multitude of cells is incorporated together
to form a large many-celled animal, it is not economical
for the incorporation that each of its cell-units should, so to
speak, go its own way and continue to perform all its func-
tions independently for itself. It is more economical,
both for the incorporation as a whole, and for each of these
cell-units, that each of the functions requisite for the com-
mon weal should be assigned to particular groups of cells —
to some groups the receiving of impressions, to other
groups the functions of digestion and assimilation, and so

I

Invertebrate Gallery of the Indian Museum. il

on : much as happens in communities of men, where the
various industries and activities of the community are not
performed by all the citizens alike, but each citizen is
devoted to one particular occupation. In this way, since
'' practice makes perfect," each function comes to be dexter-
ously and economically performed.

This apportioning of functions is known as the " physio-
logical division of labour," and we must now consider the
changes to which it gives rise.

Let us imagine a colony of cells, all of which are alike
in form, and, like a Protozoan, possess the same limited
range of ill-developed functions, and let us now suppose
that to one group of cells is allotted the function of pro-
tecting the colony from external injuries, and to another
group of cells the function of digesting the food of the
colony. Then as a natural result of special perfection in
one set of protecting functions to the relative neglect of
the digestive functions, and vice versa, these two groups
of cells will gradually come to differ in many points of
structure and form.

In other words, among cells originally alike in form
the specialization of function to which the division of
physiological labour gives rise leads to many differences
in form.

A second consequence of the physiological division of
labour, and of the differences in occupation and struc-
ture to which it leads, is that all the various cells and
groups of cells — like the citizens of a state — come to be
mutually dependent on one another.

The earlier and simpler stages of the physiological
division of labour are seen in the two large family-unions
or phyla of Metazoa known as Coelenterata, in which the
constituent cells of the body fall into two distinct well-
differentiated layers or membranes, — an external protec-
tive and sensory layer, and an internal digestive layer,—
enclosing a central cavity or stomach.

12 A Guide to the Zoological Collections in the

METAZOA CCELENTERATA.

[Case® 1—8 along the SS^stcrn sil)c, anb 9—16 along the
©astern ©ibc of the Olatlerj)].

The Coelenterata, or Zoophytes, are multicellular ani-
mals, most of which are immovably fixed and have the
power of increasing either by fission, or by budding like
plants, to form tree-like colonies.

Many of them were formerly classed with plants, and
their name of Zoophyte, or "Plant animal", indicates this
superficial resemblance.

The group includes the Sponges, the Sea-firs and Sea-
jellies, the Sea-pens, the Corals, and the Sea-anemones.

In the Ccelenterata-iy^e the division of labour has pro-
gressed to the extent of segregating the cells of which the
body is made up into two layers — an outer chiefly defen-
sive layer known as the ectoderm, and an inner chiefly
digestive layer known as the endoderm. Between these
two layers a middle chiefly supporting layer, known as the
mesoderm, is afterwards developed.

The Coelenterata are divided into two great groups —
(i) the /'^'^{/6'rrt:. or Sponges, which have inhalant pores in
the body-wall, but have no mouth, no tentacles, and no
stinging cells ; and (2) the Ctiidaria, or Stinging Zoo-
phytes, which have no inhalant pores in the body-wall, but
have a mouth, tentacles, and stinging cells.

PHYLUM I OF THE CCELENTERATA.

PORIFERA (SPONGES).

[(Eases 1—3 along the SEestern sik of the (lallevj)].
The typical form of the simple sponge-animal is that of
a tube closed and fixed at one end and free and open at

Invertebrate Gallery of the Indian Museum. 13

the other. The tube-wall is built up of three layers of
cells (1) a very thin outer layer of delicate cells known as
the ectodermal epithelium, {2) an inner layer of large cells
known as the endodermal epithelium, and (3) a middle
layer of cells and intercellular substance secreted by the
cells, known as the mesodermal connective tissue, or
sponge parenchyma. In this mesodermal tissue a sup-
porting skeleton of horn, or lime, or flint is usually de-
veloped, and it is this skeleton, washed and dried, that
constitutes most of the Museum specimens of sponges.

The hollow of the tube is known as the " gastral cavity,"
and its open end as the "osculum".

The osculum does not correspond to the mouth of other
Ccelenterates. The sponge in fact does not possess a
mouth, but the body-wall is perforated by large pores
which can be closed and opened again. Through these
pores currents of water stream into the gastral cavity^
carrying with them the microscopic organisms which form
the food of the sponge, and passing away out through the
osculum.

This simple type of sponge is seen in Ascetta, which,
however, is not represented in the collection. Such simple
forms are uncommon. In the Syconidae, of which several
specimens {Sycandra^ Grantessa, Leucandra) are exhibited
in the collection (Case 1), the mesodermal parenchyma
gets much thicker, and becomes tunnelled by pouch-like
offshoots of the gastral cavity, the ends of the pouches
opening to the exterior by pores, and causing the conical
bulgings to be seen on the outside wall of the sponge
where they open. This not very complicated type is fairly
well seen in the exhibited specimens of Sycandra and
Sycon, both of which are shown in longitudinal section, in
Case 1.

In most other cases the structure of the sponge is still
more complicated by the further thickening of the meso-
derma parenchyma and the repeated branching of the

14 A Guide to the Zoological Collections in the

pouches derived from the original gastral cavity to form
systems of canals and of chambers— the "ciliated cham-
bers " — in which all the digestive and respiratory work of
the sponge is carried on. In these cases the water carry-
ing food and dissolved air streams through the "pores"
into "afferent canals " which lead into "ciliated chambers"
that are really only special developments of the branches
of the gastral cavity. From the ciliated chambers the now
effete water passes through "efferent canals" into the
much-restricted gastral cavity, whence it streams out at
the osculum.

This complicated branching canal and chamber system
can be seen in almost any sponge, but it is specially
well seen in the exhibited vertical section (spirit-speci-
men) of the Hexactinellid sponge Pheronema globosinn^ in
Case 1.

Further complications of the sponge-form result from
the fact that many sponges increase by budding, so that
the originally single sponge becomes a colony of sponges.
This is well seen in the exhibited specimens of Sycandra^
Reniera and Chalina.

It has already been stated that a firm supporting skeleton
is usually developed in the mesoderm of the sponge, and
this skeleton, from the superficial observer's point of view,
is the principal part of the sponge, as it forms the bulk of
the animal and its roost enduring part.

With the exception of one small Family — the Spongil-
lidae--2A\ the sponges are marine, living either attached to
rocks and reefs in shallow water, or anchored in the mud
of the ocean-depths.

Sponges are divided into two great Classes — [\\Calcarea
and (2) Nun-Calcarea.

I. PORIFERA CALCAREA.

[€il5C 1].

The Calcarca consist of one Order, namely, —

Invertebrate Gallery of the Indian Museum. 15

i.— CALCISPONGIiE.

Ill the Calcispongix the sponge skeleton is made up of
spicules of carbonate of lime interlaced to form a sort of
rigid felt-work.

The Calcispongise are represented in the collection by
specimens of Ascetta, Sycon, Sycandra, Grantessa, and
Leucandra.

2. PORIFERA NON-CALCAREA.

[Cases 1—3].
In the Non-Calcarea the skeleton consists either of spi-
cules of silica (flint), or of horny fibres. There are three
Orders — Hexactinellida, Chondrospongi^, and Curnacu-
spongise.

ii.-PORIFERA HEXACTINELLIDA.

[OTasc 1].

Hexactinellida (Glassy or Flinty Sponges), in which
the skeleton consists of spicules of flint or opal. The
Hexactinellida^ which are well represented in the Museum
collection, live almost entirely in the great depths of the
ocean. They very rarely occur in less than 100 fathoms,
but are to be found at all depths between 100 and 3,000
fathoms.

In the Indian Sea they have been found at the greatest
depth at which the dredge has been used by H. M. I.
M. S. ^^Investigator'' and according to the observations of
the naturalists of this vessel they occur in the greatest
abundance in the neighbourhood of the Andaman Islands
at depths of 180 to 300 fathoms.

The skeleton in the Hexactinellida is formed of spicules
of flint or opal which are typically six-rayed, the tips of
the rays of neighbouring spicules being very commonly
cemented together by flint to form a lattice-work of re-
markable regularity, symmetry, and rigidity. This is well
seen in the beautiful Venus' Flower Basket {Euplectella),

1 6 A Guide to the Zoological Collections in the

and also in Aphrocallistes and Farrea, all of which are
exhibited in the collection.

In some species the spicules at the base (or root) of the
sponge are fused together to form stout threads, which
either remain separate or in loosely-woven tufts as in the
Bird's Nest Sponge {Pheronema globosum) and in Semper-
ella schnitzel^ or are tightly woven together in strands to
form a long rope, as in the Glass-rope Sponge {Hyalone-
ma). By these tufts or ropes the sponge anchors itself
in the mud at the bottom of the ocean.

The Hexactinellida are represented in the collection by
specimens of the following genera : — Euplectella, Au-
lochone, Nyalonema, Stylocalyx, Pheronema, Semperella,
Aphrocallistes, and Farrea. Some of the forms taken by
the spicules of the flinty sponges are shown in the large
plate of enlarged drawings in Case 1.

iii.— PORIFERA CHONDROSPONGI^.
[(Ia0c 2].

The Chondrospongise, or Horny-Flinty Sponges, form a
very large Order of sponges, in which the skeleton is
typically made up of a mass of siliceous, or flinty, spicules
of various shapes, which are not usually cemented together
either by spongin or by flint, but are matted together to
form a stout felt-work.

The Order is fairly well represented in the collection by
the following genera : — Tethya, Aulospongus ; Raphyrus,
Papillina ; Suberites, Poterion (a series of magnificent
specimens of Poterion neptuni), Raspailia, Dictyocylin-
drus, Acanthella, Phakelliay Chondrilla, Spongilla.

iv.— PORIFERA CORNACUSPONGI.^.

[Case 3].

The Cornacuspongise also form a large Order, in
which the skeleton is typically made up either of siliceous

Invertebrate Gallery of the Indian Museum. 17

spicules cemented together by a substance known as
" spongin " chemically very similar to horn, or is formed
entirely of spongin fibres without any spicules whatever.
The common bath-sponge is a familiar example of this last
group. In Halme the horny skeleton is strengthened with
grains of sand. The Cornacuspongix are represented in
the collection by the following genera : — Esperella, fo-
trocha, Clathria, Echinonetna^ Plumohalichondria^ Clath-
rtssa, Thalassodendron, Echinodictyum, Caulospongia ;
Reniera, Haplochalina, C/ialinissa, Chalina, Tuba ;
Phyllospongia, Chalinopsilla, Hippospongia, Halme, Stel-
osf)otigia, Hircinia, Cacospongia, Carterispongia, and
Dendrilla.

PHYLUM II OF THE COELENTERATA.

CNIDARIA (STINGING ZOOPHYTES).

[Cases 3—16],

The other great group of the Coelenterata is that of the
Cnidarta, or Stinging Zoophytes, distinguished from the
Porifera or Sponges in possessing for the ingestion of food
a mouth surrounded by tentacles, instead of pores, in
being provided with special stinging-cells for defence and
for disabling their prey, and in being possessed of a true
stomach, as well as of the elements of a muscular and
nervous system.

There are two great divisions of the Cm'daria, namely,
(i) the division typified by Hydra, in which the mouth is a
simple orifice in the body-wall, and leads directly into the
stomach ; and (2) the division typified by the Sea-anemone,
in which the mouth is formed at an invagination of the
body-wall, the invagination forming an ectodermal gullet.
Of these two divisions the first consists of the one Class
Hydrotnedusse, and the second consists of three Classes
the Ant ho 20a, the Scyphomedusse, and the Ctenophora,

B

A Guide to the Zoological Collections in the

I. CNiDARiA HYDRO MEDUSiC.

[OTas^s 3—4].

In this great Class the type is an animal having the form
of a simple tube closed and often attached at one end — the
aboral pole ; and provided at the other end (oral pole)
with a mouth surrounded by tentacles. The tube of which
the animal consists is mainly formed of two layers, — an
outer layer or ectoderm, and an inner layer or endoderm —
and between these two there occurs the elements of a
third supporting layer, or mesoderm. The hollow of the
tube is the gastric cavity, or stomach.

This simple type is seen in Hydra, an animal that can
only be properly examined under the microscope, and
which is therefore exhibited in the form of an enlarged
drawing.

This simple type becomes complicated by the fact that
the parent polyp usually buds and branches again and
again — the resulting offspring remaining united together
and to the parent to form a tree-like colony.

This is well seen in the exhibited specimens of Tiibu-
laria, Eudendrium, Corydendrium, Plumularia, and Ser-
tularia.

In these colonial forms the units of the colony are
known as "zooids," and the fleshy substance which binds
them together is known as the "coenosarc." In the ecto-
dermal coenosarc a protective and supporting investment
is often secreted. In Tubularia and the allied forms this
is a chitinous pellicle. In Perigonimus the chitinous pelli-
cle is strengthened by grains of sand. In Plumularia
and Sertularia the chitinous investment is very thick
and stout, and is moreover continued over the zooids up
to the level of their tentacles to form protective cups
into which the zooids can completely retract themselves
when alarmed. In Millepora, instead of a membranous
or chitinous pellicle, a hard stony deposit, in structure ex-
actly similar to a stony coral, is formed by the ectoderm.

Invertebrate Gallery of the Indian Museum. ig

and into cavities in this the zooids can withdraw them-
selves. All these gradations may be well studied in the
specimens and models exhibited in the collection. (Cases
3-4).

Another complication found in these compound colonies
is due to the fact that a physiological division of labour
takes place among the zooids of which the individual
colonies are composed, some of the zooids remaining
devoted entirely to nutritive functions and retaining the
hydroid form, while others become specialized for repro-
duction, and undergo much modification in form. The
essence of this modification is that the reproductive zooids
(or "gonozooids") lose their fixed attachment and become
free-swimmers. The explanation of their becoming free-
swimmers is that the eggs and young which they produce
may be widely scattered, and so may be more likely to find
food and to live and grow than they would be if they fell
close to the already well-established parent colony.

The reproductive polyps are known as Medusse .- they
may be regarded as hydra-ioxm polyps, which have become
greatly flattened out at the aboral pole into a disk, and
then bent round into the form of a bell, from the centre
of which the oral end of the polyp (the mouth) hangs
down like a hollow clapper (" manubrium " or " gastric
peduncle ").

At the same time the mesoderm in the wall of the bell
becomes much thickened, and the gastral cavity in the
wall of the bell becomes obliterated, except at the cir-
cumference of the bell, where it remains as a canal ("cir-
cumferential canal"), and along certain definite lines
(usually four in number) which lead from the cavity of the
clapper or gastral peduncle to the circumferential canal.
These canals are known as " radial canals", and they
carry digested nutriment to all parts of the bell. They are
well seen in the spirit-specimen of Olindias mulleri,
in Case 3,

Further, the inside edge of the bell becomes thickened

B2 '-^

I

20 A Guide to the Zoological Collections in the

to form a ring of muscle, by the contraction of which, under
the control of a double ring of nerve-tissue, the Medusa
swims through the water, and along the edge of the bell
tentacles and sensory organs (auditory and visual) are
developed at the point where the radial canals join the
circumferential canal : these sense-organs are never cover-
ed over by folds of membrane. The development of the
Medusa from the ordinary nutritive-zooid type into the
free locomotive gonozooid type is well displayed in the
enlarged glass-models of Bougainvillea fmticosa, Syn-
coryne frutescens, Perigonimus vestitus^ etc., in Case 3.

From such a typical Medusa-iorm two other modifica-
tions arise, one being of the nature of an advancement,
the other being probably a degradation.

The advanced type of Medusa is shown in the beauti-
ful specimen of OUndias miilleri, a large Medusa which
throughout its life is known only as a free animal, and
never springs as a bud from a tree-like colony. The same
thing is illustrated in the series of models of Carmarina
has tat a.

The degraded type of Medusa is seen in the exhibited
specimens of Sertularia, and in the beautiful spirit-speci-
men of Tubularia larynx^ where the reproductive units
of the polyp-colony, instead of breaking away and becom-
ing freely locomotive Medusae with mouth and tentacles,
merely grow into large buds or sacks, without mouth and
tentacles, in which the reproductive elements are developed.

These arrested or incompletely developed Medusae are
usually known as " Medusoid gonophores."

An intermediate step, in which the reproductive zooid
(gonozooid) becomes developed into a more or less perfect
Medusa, wliich, however, never becomes detached from the
parent colony, occurs, and is represented in the collection
by the enlarged models of Tubularia indivisa, in Case 3.

In some Hydrozoa the physiological division ot labour
goes far beyond the simple separation of the units of the
colony into two classes of zooids, the nutritive and the re-

I nvertehrate Gnllcry of the Indian Museum.

productive. For example, in the Millepora, as is shown in
the enlarged drawings after Moseley, the colony consists of
a multitude of polyp-like zooids bound together by a hard
stone-like ccenenchyma, as is seen in the exhibited speci-
men. The zooids are grouped together in little groups of
six, in each of which the central zooid is short and stout
with a mouth and few tentacles, while the five peripheral
zooids are long and thin and flexible, and have no mouth
but numerous tentacles. The central zooid, or gastrozooid,
is specially modified to perform the work of digestion for
the colony ; while the long thin zooids (dactylozooidsj are
specially modified to catch prey, which they convey to the
mouth of the gastrozooids. The food digested by the gas-
trozooids circulates in canals in the ccenenchyma, and is
thus distributed all over the colony and to the dactylo-
zooids, just as in other Hydrozoa.

In the Siphonophora^ which are represented in the col-
lection by the glass models of f hysophora^ Apolemia,
Agalmopsis, Halistemma, and Physah'a, the entire colony
is freely locomotive, usually near the surface of the open
sea, and the physiological labours of the colony are allot-
ted to separate groups of units or " persons," each of which
becomes specially modified for the sole performance of its
own function. The exhibited specimen of Physophora
hydrostatica may be taken as an illustration : here the
labour of the colony is much subdivided, and of the polyps
some are exclusively devoted to moving the colony about
("locomotive persons") and have a modified Medusa form,
others are exclusively concerned with the digestive labours
of the colony ("nutritive persons"), and have become
transformed into simple tubes for taking in food, others are
entirely occupied with the mechanical protection of their
fellow-workers, and have become simple shield-like plates
("protective persons"), others are completely engaged in
active defence or in offence, and have become changed into
long grappling lines furnished v/ith batteries of stinging-
cells, while others are " reproductive persons/' and are prac -
lically nothing but bunches of egg-capsules. Ail these

22 A Guide to the Zoological Collections in the

differently occupied and variously modified " persons " are
indicated by letters on the life-sized models in Case 3.

Such colonies, made up of units of many different forms,
are known as Polymorphic Colonial Hydrozoa,

Almost all the Hydrozoa are marine, Hydra being the
best known of the very few freshwater forms.

The fixed Hydrozoa usually live attached to rocks or
encrusting sea-weeds, dead shells, etc., between low water
mark and lOO fathoms; a few are known from the deep
sea ; while some species attach themselves to freely loco-
motive animals, such as crabs, fishes, etc., by which arrange-
ment they greatly profit. The free-swimming Medusas
are found at the surface of all the seas and oceans.

Not to include the usual glass models, the Hydrozoa
are represented in the exhibited collection by spirit-speci-
mens of the following genera : Tubtilaria, Eudendrium,
Corydendrium, Cordylophora, Olindias, Sertularia,
Plumularia, A nt ennui aria , only the last three being from
the Indian Seas,

2, 3, 4. CNIDARIA ANTKOZOA, SCYPHOMEDUS/E, AND
CTENOPHORA.

[Cla0£0 4—16].

In the second division of the Cnidaria or Stinsfine
Zoophytes the mouth is formed, as in all higher animals,
by an invagination of the ectoderm. The mouth, therefore,
does not open directly into the gastric cavity as it does
in the Hydrozoa, but into an ectodermal invagination, or
gullet, which leads to the gastric cavity or stomach.

There are three distinct and equivalent types or Classes
of these more highly developed Cnidaria, (i) the Anthozoa-
type, of which the Sea- anemones and Coral polyps are
good examples, (2) the Scyphomedusa-ty^e, of which the
large Acraspedote Medusa are the examples, and (3) the
Ctenophor type.

In the typical Anthozoan the form of the body is still a
three-layered tube usually closed and fixed at one end, free

Invertebrate Gallery of the Indian Museum. 23

and provided with a mouth surrounded by tentacles at the
other — the hollow of the tube forming the gastric cavity or
stomach.

The gastric cavity is divided into compartments along
its whole length from pole to pole by radial partitions
formed by outstanding ridges of endoderm and mesoderm —
these being known as sarco-septa or mesenteric folds.

2. CNIDARIA ANTHOZOA.

[dases 4— X6, toith the cxaptiou of a ©itigle com^jartment ai
QTase 7 0aupii;li bu .SruphomtbusiC vtnl) €tenophora].

The Anthozoa comprise the Sea-anemones and various
kinds of Corals, and form a very large and important
group. They are all marine animals. The Corals especially
are of much interest, because they give rise by budding and
fission to great branching tree-like or turf-like colonies,
the massing together of which in the shallower waters of
tropical seas forms reefs of vast extent. These reefs often
become at places raised to the sea level, and they then
constitute the nuclei of groups of islands. Good examples
of such coral islands near at hand are the Laccadive and
Maldive Archipelagos.

The Anthozoa are divided into two sub-Classes — the
Actiniomorpha and the Alcyoniomorpha.

a. ANTHOZOA ACTINIOMORPHA.
The Actiniomorpha are divided into three Orders
Actiniaria, Antipatharia, Madreporaria.

i. ANTHOZOA ACTINIOMORPHA ACTINIARIA.
[JEibile of (Ease 7].
The type of simple Actiniomorph Anthozoan is the Sea-
anemone (Actinia), of which there are numerous examples
exhibited, both glass models and actual spirit specimens,
in Case 7. From an inspection of one of these it will be
seen that the sea-anemone consists of a tube usually

24 A Guide to the Zoological Collections in the

attached at its aboral pole, which is known as the pedal disk
or foot-plate, and provided with a mouth and crown of hol-
low tentacles at the oral pole, which is known as the oral
disk or peristome. In Polysiphoma, a deep-sea form,
shown in the Case, the tentacles are reduced to short broad
stumps, each of which has an orifice at the end through
which water with nutrient particles can enter the gastric
cavity. The hollow of the tube forms the stomach, into
which the pendent oesophagus opens, as may be seen in
the several longitudinal bisections of Sphenopiis. The wall
of the stomach is raised to form sarco-septa or mesenteric
folds, to the free edges of which are attached bunches of
filaments (mesenteric filaments) and acontia. The latter
are freely armed with stinging-cells, and can be protruded
rapidly from the mouth, and sometimes through the body-
wall, in defence, when the sea-anemone is irritated. From
the free edges of the mesenteric folds the reproductive or-
gans also arise. The sarco-septa, or mesenteric folds, with
their bunches of mesenteric filaments and of generative
products are very clearly displayed in the longitudinal
bisections of Sphenopiis and Cerianthus. The acontia are
beautifully seen in ,the longitudinal bisection of Cerian-
thus, fringing the lower end of the septa.

The tentacles in the Actiniaria are multiples of six :
they are usually retractile, as is seen in the sections of
Sphenopus, and their function is to seize upon prey and
convey it to the mouth.

Most of the sea-anemones have soft bodies, but some,
as in the exhibited specimens of Sphenopus arenaceus and
Sphenopus marsupiaiis, and oiZoanthus and Episoanthus,
have a leathery external coat, which is further strengthened
by a layer of sand-grains agglutinated together. The
interesting form Cerianthus, too, some large specimens of
which are to be seen in the Case, is furnished with a thick
jacket made of mucus and mud and sand, into which the
animal can retract itself.

Most of the sea-anemones are simple, that is to say

Invertebrate Gallery of the Indian Museum. 25

they do not form colonies by budding and fission, but
Zoanthus and Epizoanthus are exceptions to this rule,
and form encrusting colonies on shells and very often on
the anchoring strands of the Glass-rope Sponge.

The sea-anemones usually live attached to rocks between
tide-marks or not far below low-water mark. Some, as
Sphenopus. and Cerianthus, which live in deeper water
are not fixed, but bury their bodies in the mud of the sea-
bottom, leaving the mouth and tentacles exposed. A few,
as Polysiphonia, live on the soft mud of the ocean-bottom
at the greatest depths.

Many sea-anemones attach themselves to the carapaces
of hermit-crabs or other soft-bodied Crustacea, by whom
they are carried about from one feeding-ground to another,
the anemone paying for this service by affording the
necessary protection to the soft-bodied crab. This inter-
change of services between two animals, both of which live
in other respects a completely independent life, is known
as commensalism.

When an animal such as a simple sea-anemone gives
off buds, or splits itself into two longitudinally to form
new " persons," and when these newly-formed "persons"
remain attached to the parent and themselves give rise
to another generation which also remains attached, and
when further the parent and all its attached generations
of branching offspring secrete in their outer layer or
ectoderm a hard protective coat of carbonate of lime, we
then get the common forms of stony-coral. The stone
coral, or Madreporarian, is in fact simply a sea-anemone
or colony of sea-anemones with a calcified integument.

ii. ANTHOZOA ACTINIOMORPHA MADREPORARIA.

The stony corals {Madreporaria) do not all form
colonies, but they all secrete in the outer layer of their

26 A Guide to the Zoological Collections in the

integument the stony protection and support known as
"coral." The coral, or " corallum," when freed from the
soft parts of the animal by maceration (as is done in most
Museum specimens) consists of an outer cup or " calice,"
which usually contains a central upstanding column or
"columella " and numerous series of vertical plates radia-
ting from the columella to the calice wall — the *'sklero-
septa" and " pali " — by w^hich the mouth and tentacles
are supported. The vertical section through the corallum
of Caryophyllia communis in Case 16 shows this well.

The living Madreporaria are divided into three sections
— the (i) Madreporaria Aporosa, (2) Madreporaria Fun-
gida^ and (3) Madreporaria Perforata.

MADREPORARIA APOROSA.

[(Eas^s 14-16].

In the Madreporaria Aporosa the corallum has a solid
wall and solid septa. This section is divided into four
families — the Turbinolidx, the Oculinidie, the Pocillopori-
dse, and the Astr^idx.

ist Family Turbinolidas— In which the corallum is almost
always a single simple calice or cup, with the chambers
between the sklero-septa (" interseptai loculi ") open to
the bottom of the cup. Branching colonies never occur
and the Turbinolidge therefore play no part in the forma-
tion of coral reefs.

Many of the Turbinolidx live at the bottom of the deep
sea, where sometimes, as in the case of Caryophyllia cotn-
munis, they occur in large beds. This family is represent-
ed in Case 16 by the following genera, all of which occur in
Indian waters : — Flabellum, Rhizotrochus, Deltocyathus,
Paracyathus^ Heterocyathus, Caryophyllia^ Stephano-
trochus, Discotrochus, and Poiycyathus, the latter being
one of the very few Turbinolians that form colonies.

Invertebrate Gallery of the Indian Museum. 27

2nd Family Oculinidge — In this family the corallum is
always compound, forming tall branching colonies, the
calices or cups of the individual corallites being borne on
the sides and tips of the branches. As growth goes on, the
calices often fill up with stony deposit. So far as is known
only two species of Oculinidge occur in Indian waters,
namely, Lophohelia and Cyathohelia. The Ocultnida^ are
represented in Case 16 by the following genera : — Lopho-
helia from the depths, Cyathohelia from the Madras coast
and from Japan, and Amphihelia from Japan.

3rd Family PocllIoporJdse. — In this family the coral
consists of a branching tree-like colony bearing crowds
of small calices with small or rudimentary septa — the
calices often filling up with stony deposit.

The Pocilloporidse consist of only two genera —
Pocillopova and Seriatopora, both of which are common
reef-forms, and are found in abundance in the shallow
waters of the Indian Seas. Numerous species are repre-
sented in Case 16.

4th Family Astrasldse. — A very large family, some of
which are simple, but the majority of which form the
great massive boulder-like colonies of the coral-reefs. In
structure the Astraeoid much resembles the Turbinoloid
coral, but the corallum in the Astraeidse differs in havino-
the chambers between the septa (interseptal loculi) more
or less crossed by strands of coral known as "dissepi-
ments."

The Astrxidai are represented in Cases 14-15 by the
following genera — all from the coral-reefs of the Indian
Seas : — Montlivaltia, one of the simple Astrseans which
does not form branching colonies ; Cylicia, one of the
genera which forms creeping colonies ; Cladocora, Tra-
chyphyllia, Mussa, Euphyllia, Mxandrina, Cceloria,
Symphyllia, Tridacophyllia, Hydnophora^ Favia, Goni-
astrsea. Phymastrxa, Plesiastrsea, Echinopora, Galaxea
Leptastrsea^ Prionastrsea, Mcrulina — all these last being
true reef-corals forming branching or mpssive turf like
colonies.

28 A Gutde to the Zoological Collections in the

MADREPORARIA FUNGIDA.

[arjts£ 13],

The majority of the corals of this section are flat
mushroom-like forms : the chambers between the sklero-
septa (" interseptal loculi ") are always more or less filled
up by bars of coral ("dissepiments "), which pass across
from septum to septum, and the calice-wall is usually
fenestrated or perforated to a certain extent. The Fimgida
are divided into five families — two of which, however, are
extinct, being known only as fossils. The three living
families are the Plesiofiingidse, the Fungidx, and the
Lophoseridse.

1st. The gene/a of the Plesiofungidae are all extinct
but one ~Std era iirxa — which lives in the Indian Seas,
a specimen being exhibited in Case 13-

2nd Family Fungidae. — The corals of this family are
larcre flat mushroom-shaped disks, with perforated and
fenestrated walls; some are simple and some compound.
They are well represented in Case 13 by numerous beau-
tiful specimens, from the Andaman and Mergui reefs, of
the following genera : — Fimgia, Haliglossa, Halomitra
{Podobacici), Cryptahacia^ Herpolitha^ Lithactinia.

3rd Family Lophoseridae. — In this family the calice-wall
IS not perforated or fenestrated, and the corals are either
simple and small, flat and mushroom-like, or else they are
compound, and form spreading encrusting fungus-like cakes.
They are well represented in Case 13 by the following
genera : — Trochoseris^ Cycloseris, Diaseris, and the beauti-
ful Bathyactis from the depths of the Bay of Bengal — all
these being small simple forms : and Lophoseris {Pavonio),
Leptoseris, Agaricia, Coscinarxa, and Psammocora —
which are compound forms.

MADBEPOKAKIA PERFORATA.

[Cases 8-12].
In th's section, which includes both small simple corals
and huge trec'like colonies, the great distinguishing char-

Invertebrate Gallery of the Indian Museum. 29

acter is that both the walls of the coral-cups and the
branches are spongy and porous or lace-like. The Per-
forate Madreporaria are divided into three families — the
Eupsam?nida;, the Madrepcridx, and the Poritidse.

1st Family Eupsammidse. — The Eupsammidai are mostly
small simple corals, but some of them, e.cr., DendropJiyl-
lia, form colonies. They are represented in Case 12 by
the following genera from the rocky parts of the coasts of
India, Burma, and Ceylon : Balanophylh'a, Eupsammia
Heteropsatnmta, Dendrophyllia^ Ccenopsam?7tia, Astro-
psammz'a, and Rhodopsammia.

2nd Family Madreporidas. — The Madrepores are the
typical corals of the reefs of all parts of the world, where
they occur as large tree-like colonies of singular beauty.
A large number of species of the genera Madrepora and
Turbinaria are shown in Cases 9-12, all of them being
from the reefs and islands of the Indian Seas

3rd Family Poritidse. — In this family not only the
coral-walls, but the septa also, are porous and lace-like :
the corals are always compound, and the individual coral-
lites are very small. The colonies are usually in the form
of tufts or boulders, and are very common constituents of
coral-reefs. Numerous species, from the reefs of the
Indian Islands, of the following genera, are exhibited in
Case 8 '.—Porites, Synarsea, Goniopora, Alveopora {Favo-
sitipora), and Montipora.

In connexion with these exhibits of corals, it must be
remembered that almost all Museum specimens are sim-
ply denuded and dried skeletons. The appearance of the
living coral is well seen in the wax models of y^.y/r^;/^'^^-
(in Case 12), and of Caryophyllia smithii (in Case 16),
and can be fairly well understood by examination of the
spirit specimens of Bathyactis stephanus (in Case 13), and
of Flabellumjaponicum^Flabellum lacimatum,znd Rhizo-
trochus crateriformis {\x\ C3iSe\G), where the spirit-pre-
'jprved specimens, with the soft parts intact though much

30 A Guide to the Zoological Collections in the

retracted, can be compared with the denuded and dried
coralla alongside.

ill. ANTHOZOA ACTINIOMORPHA ANTIPATHARIA.

[^owth^vn txxt of Qla0£ 7],

The Antipatharia constitute a small group of Ac-
tiniomorpha which, like the true corals, form branching
tree-like colonies supported by a rigid skeleton. The
skeleton of the Antipatharia differs from that of the Mad-
reporaria in being formed of horn instead of stone, and in
being developed only in the coenenchyma and not round
the polyps themselves, which are quite soft, like a sea-
anemone. The Antipatharian corallum, in short, much
resembles the corallum of the Gorgonacea next to be de-
scribed, the resemblance being so complete as to have
misled the older zoologists into classing the Antipatharia
with the Alcyonaria. When, however, the living polyps
are examined, the Antipatharia are found to agree with
the Actiniaria in having tentacles in sixes or multiples of
six, and in having usually numerous septa, instead of, like
the Alcyonaria^ eight tentacles and eight septa.

The black skeleton or corallum of the Antipatharia^
moreover, can be at once distinguished from that of the
Gorgonacea in being densely covered with little thorns.

The Antipatharia are represented in Case 7 by the
dried tree-like skeletons of Antipathes and Cirrhipathes,
by the fine spirit-specimens of the same genera, in which
the little polyps with their coenenchyma can be seen in-
vesting all the twigs and branches of the corallum like a
soft bark, and by the fine specimens of Bathypathes, a
deep-sea genus.

Bathypathes is a remarkable type which is distinguished
from all other Actiniomorpha by exhibiting the phenome-
non, already described, of dimorphism : that is to say,
in every colony some of the units are specially modified to
perform only reproductive functions (reproductive zooids

Invertebrate Gallery of the Indian Museum. 31

or gonozooids), while the others are specially modified to
perform only nut:itive functions (nutritive zooids or gas-
trozooids).

The Antipatharia usually encrust rocky bottoms at
moderate depths, — 30-60 fathoms. The few deep-sea forms
are also rock livers.

b. ANTHOZOA ALCYONIOMORPHA.

[Cases 4—6].

This sub-Class consists of marine reef-living animals
very commonly in the form of branching tree-like colo-
nies or of encrusting moss-like or fungus-like colonies,
the constituent units or " persons" of which have the typical
polyp shape and structure.

Each polyp usually has eight tentacles, instead of six
or a multiple of six tentacles, as in the Actiniomorpha.
The possession of eight tentacles and eight septa is in short
the principal constar^i, character of the Alcyoniomorpha.
The tentacles, moreover, are pinnate.

The Alcyoniomorpha, like most of the Actiniomorpha^
secrete a firm supporting skeleton or coral, which, however,
differs from that of the Actiniomorpha, not merely in
being less stony and rigid, but often in important points
of development.

The skeleton or "coral" of the Alcyoniomorpha (i)
is sometimes formed entirely by the mesoderm, in which
calcareous spicules are deposited to finally fuse together
into a hard solid wall : such a mesodermal coral is seen in
the specimens of Tubipora musica (the organ-pipe coral)
and of Telesto arborea ; but (2) is most often formed by
both ectoderm and mesoderm, the mesodermal element,
however, greatly preponderating. la this case the polyp,
at the point where it attaches itself to the ground, secretes
between its ectoderm or outside layer and the ground a
layer of horny matter, and as the polyp-stalk grows up-
wards this horny mass follows, until it forms a central
horny core or axis which follows the polyp-stalk in all its

32 A Guide to the Zoological Collections in the

branchings : so that in this way the horny substance which
was originally on the outside of the base of the polyp
comes to occupy the central core of the polyp-colony.
Round about this horny axis of ectodermal origin masses of
calcareous spicules are deposited, and these often fuse to-
gether or interlace to form a thick rigid coral. Such a
coral, formed of both ectoderm and mesoderm, is found in
Gorgonia.

The Alcyoniomorpha are divided into three Orders,
the Alcyonacea, the Pennatulacea, and the Gorgonacea.

i. ANTHOZOA ALCYONIOMORPHA ALCYONACEA.

[ara0£ 4].

In the Alcyonacea there is no horny central axis of
ectodermal origin, and the units of the polyp-colonies are
united either by a thick fleshy ccenosarc in the mesoderm
of which calcareous spicules are secreted, or by a hard
calcareous coenenchyma. The coenosarc is tunnelled by
canals which are continuations of the gastric cavities of
the polyps, and by these canals (" nutritive canals ") nu-
triment is distributed throughout the colony. The nu-
tritive canals are well seen in the vertical section of Alcyon
ium glaucum^ and in the transverse section of Spon-
godes, in Case 4.

The Alcyonacea are represented in Case 4 by the fine
spirit specimen of Telesto arborea, by the series of dried
coralla (mesodermic) of Tubipora musica, by the spirit
specimens of Alcyonium^ Lobularia, and the fine series of
species of Spongodes, and by the dry specimens and draw-
ings of Heliopora. In Spongodes the colony has the form
of a bush, in which the coenosarc forms a root and stem
and branches, and the polyps occupy the sides and tips of
the branches like leaves or flowers.

In Heliopora the coenenchyma has become calcified
and forms a crystalline stony mass, like the coral of a
Madreporarian.

Invertebrate Gallery of the Indian Museum. 33

In Tubipora the ccenenchyma consists of a mass of tubes
shaped like organ-pipes.

The Alcyonacea mostly inhabit the reefs and rocks of
shallow waters, encrusting rocks, dead coral, etc., with
their funeus-like and shrub- like colonies.

ii. ANTHOZOA ALCYONIOMORPHA PENNATULACEA.
[dase 4].

In the Pennatulacea^ which comprise the Sea-pens,
Sea-feathers and Sea-rods, the polyp-colony consists of a
more or less fleshy stem (coenosarc), one end of which is
buried in the mud, while at the other end are borne the
polyps, either on regular bilateral overlapping leaf-like
plates (as in Pteroeides^ Godeffroyia^ Pennatula^ Hali-
sceptrum, Virgularia, and Scytaliiim)^ or sessile on the
stem in a long row or rows {Leptoptilum), or in a bunch
at the end of the stalk [Umbellula), or in a head, like
the radiating florets of a dahlia {Veretillumy Cavernu-
laria). In most cases the fleshy stem is strengthened by
a deposit of calcareous salts in the mesoderm, and in
Virvnlaria the central axis of the stem forms a riafid rod.

Examples of all the above genera (specimens preserved
in alcohol) are to be found in Case 4,

The Pennatulacea are mostly adapted for life on the
muddy bottom of shallow seas, but Umbellula and Leptop'
tiluin are peculiarly deep-sea forms.

iii. ANTHOZOA ALCYONIOMORPHA GORGONACEA.
[dascs 5-6].
The Gorgonacea include the Sea-mats and Sea-fans,
and form a large group. The polyp colonies in this
group consist of a hard, often horny and flexible axis,
which is covered by ccenenchyma from which the little
polyps protrude. Calcareous spicules are usually deposit-
ed in the ccenenchyma, so that the " coral " of the Gorgon-
acea consists of two elements — a hard or horny central

34 -^ Guide to the Zoological Collections in the

axis or core, and a spicular skin or rind. The Gorgon-
acea, like the Alcyonacea, are usually found encrusting
coral-reefs, and rocky banks in shallow water, but they
also occur in considerable abundance in the great depths
of the sea up to 1,200 fathoms, and a few species have
been found in the ab3^sses of the ocean.

In Cases 5-6 the Gorgonacea are exhibited. Of shal-
low-water forms (surf-line to 40 fathoms) the following
Indian genera are represented : — Solenocaulon, Sclero-
gorgia [Rhipidigorgia and Pterogorgia), Melithsea,
Mopsea, /sis, Acanthogorgia, Afuricea, Paramuricea,
Leptogorgia, Eunicella, Gorgonia, Juncella, Ctenocella,
Gorgonella, Verucella^ Scirpearella. While of deep-sea
forms fine alcoholic specimens of the following beautiful
species occur : — Strophogorgia ver villi, Ceratoisis grandi-
Jlora, Acanella fruticosa, Calypterinus allmani, Stenella^
Thouarella, Callistephanus koreni.

To these beautiful specimens, which were dredged by
the "Investigator," most of them in the Laccadive Sea at
about 700 fathoms, attention is particularly directed.

3. CNIDARIA SCYPHOMEDUS/E.

[J^orth^rn mh of Ca0£ 7].

The Scyphomedus£Cy or Acraspedote Medusa;, are ani-
mals of the Anthozoan type modified for a free-swimming
life at the surface of the ocean. They may be looked
upon as Anthozoan polyps that have become converted
into swimming-bells by a flattening out and cupping of the
body, just as the Craspedote Hydroniedusx may be de-
rived from the Hydrozoan polyp type.

In the case of the Scypho^nedusae, however, this meta-
morphosis has no special relation to reproduction, and the
Scyphomedusx are usually throughout the whole cycle of
their existence free-swimming Medusse^ giving rise by re-
production not to polyp stocks, but to Medusa; like the
parent.

Invertebrate Gallery of the Indian Museum. 35

The Scyphomedusx^ or Acraspedote Medusa;^ besides
being very much larger, differ from the Hydromedusx, or
Craspedote Medusa, in the following essential points : —

(i) The muscle at the circumference of the medusa-
bell never projects into the cavity of the bell to
form a ' velum.'

(2) Instead of a velum we find the edge of the swim-

ming-bell produced into variously complicated
lobes and filaments (marginal lobes) into which
prolongations of the gastric cavity extend.

(3) The manubrium, or gastric peduncle or oral tube,

of the medusa-bell is provided with an ecto-
dermal oesophagus or gullet, and the edge of the
mouth is generally prolonged into long oral
arms.

In some Scyphomedusse (the Rhizostomse) these
oral arms become deeply grooved, and the
edges at last curl over and meet to convert
the groove into a tube which, however, remains
unclosed at certain spots known as ' suctorial
mouths." The tubes of the oral tentacles lead
into the gullet, while the true mouth becomes
closed.
(4) Where the ectodermal oesophagus joins the true
endodermal gastric cavity special gastral fila-
ments, or gastric tentacles, usually in tufts,
are developed.

(5) Another important difference, which, however,

does not hold good throughout, is that the Cras-
pedote Medusa; {Hydromedusae) very seldom
(only in one family) give rise to secondary
medusae asexually by budding, whereas repro-
duction by asexual budding is not uncommon
among the Scyphomedusx. This is well seen
in the sflass model of Lucernaria.

o

(6) The sense-organs at the edge of the umbrella are

always covered.

36 A Guide to the Zoological Collections in the

(7) The generative products arise in diverticula of the
stomach, and not, as in the Hydromedusse (as
is so well shown in Olindias millleri), from
the ectoderm.
The Scyphomedusx are usually free-swimmers through-
out the whole of their existence, but in the family Lucer-
naridcB they are attached by their aboral pole in the adult
stage ,

The Scyphomedusx being exceedingly delicate animals,
are not easy to preserve for Museum purposes, and in this
collection they are represented only by the usual glass
models, and by spirit specimens of the deep-sea form
Atolla.

4 CNIDARIA CTENOPHORA.

[Ilorthcm txCss of Cnsf: 7].

In the Ctenophora the simple polyp type is much modi-
fied, and, as in the Scyphomedusse, the modification is such
as to fit the animal for a freely locomotive life at the
surface of the ocean. Locomotion, however, is effected
not so much by the contraction of muscles as by the
rowing action of special processes of the ectodermal
cells known as "cilia." The cilia are collected together
in rows which much resemble combs (hence the name
Ctenophora or "comb-bearers"), and the combs of cilia are
usually disposed in eight bands or meridians which pass from
pole to pole of the usually spherical or ovate or helmet-
shaped body. These rows of combs of cilia are very well
displayed in the spirit specimens of Beroe ovata and Cydippe
plumosa. The internal structure of the typical Ctenophor
is not essentially different from that of the Medusa : the
mouth leads by a much-compressed gullet into a long
stomach placed crosswise to the gullet, and from this
stomach a number of canals radiate throughout the bedy.

The sensory organ of the Ctenophors is single and is
situated at the aboral pole of the body. 1 he Ctenophora
are very delicate animals, and are very difficult to preserve,

Invertebrate Gallery of the Indian Museum. 37

and are therefore seldom met with in Museum collec-
tions.

In this collection they are represented at present only
by the alcoholic specimens already named, and by glass
models of Mertensia and Cestum veneris.

Cestum veneris, however, is an unusual form, for the
reason that its body is much compressed and elongated.

Cydippe 2iX\6. Beroe are the typical forms.

METAZOA CiXLOMATA.

We next come to the CcElomata, or animals that pos-
sess a true body-cavity, or coelom, through which the
alimentary canal runs somewhat like a lamp-chimney
through a lamp-globe. The coelom is a closed cavity and
lodges, besides the alimentary canal and the glands acces-
sory to digestion, at least the organs of circulation, excre-
tion and reproduction.

In the Coelomata the differentiation of the cells of
which the body is built up has become so complicated that
it is only in the very earliest stages of development that
the simple division into three germinal layers — ectoderm,
endoderm and mesoderm — is to be verified.

In a majority of the Coelomate phyla we are able to dis-
tinguish an anterior end or head, just behind which the
mouth opens ; a posterior end at which the vent opens ; a
ventral surface turned towards the ground upon which
the animal moves, and opposite to it a dorsal surface ; and
in most a plane carried vertically through the body, along
its whole length, from dorsum to venter divides the body
into two practically symmetrical halves.

The first phylum, or family union, of the C(£lomata is
formed by the Platyhelminthes or Flat-worms in which the
body-cavity is imperfect and parenchymatous, and the in-
testine, except in the case of the one Class of Memertines,
either ends blindly or is entirely absent.

38 A Guide to the Zoological Collections in the

PHYLUM I OF THE CCELOMATA.

PLATYHELMINTHES.

[5Ke0tcrn mM-t^u 46].
The Platyhelminthes include four natural groups,
namely, (i) the Turbellaria, (2) the Trematoda, (3) the
Cestoda^ and (4) the Nemertina. Of these the Cestoda and
Tretnatoda are entirely parasitic, and are therefore much
degraded in form, the alimentary canal being either absent
or incomplete. The only characters that are common to
all four groups are that the body is flat and more or less
elongated and solid, and that the nervous system is concen-
trated in a mass or " ganglion " at the head end. Repro-
duction is usually sexual, but may sometimes, especially in
the larval stages, take place asexually.

I. PLATYHELMINTHES TURBELLARIA.

[®£stertt ®aU-ra0£ 46].

The Turbellaria are small Platyhelminthes with a leaf-
shaped body: some live in the sea, some in freshwater, and
some in damp places on land.

The main features of their organization are illustrated
by enlarged drawings of Planaria polychroa and Planaria
lactea and of Cycloporus papillosus (Case 46), in which
the body-cavity is seen to be filled with parenchyma and the
intestine to end blindly.

2. PLATYHELMINTHES TREMATODA.

[SJUestcrn ® all-case 46].
The Trematoda, or Flukes, also are small Platyhel-
minthes usually with a leaf-shaped body. They are para-
sitic, commonly in the alimentary canal of warm-blooded
vertebrates, whence they sometimes pass into the portal
vein and its affluents : other forms are found in the gill-
chambers of fishes, in the bladder of the frog, etc. In order

Invertebrate Gallery of the Indian Museum. 39

to secure their hold upon the walls of these cavities the
Trematoda are furnished with large suckers for adhesion.
The intestine ends blindly. The Trematoda are represented
in Case 46, by specimens of Distoma hepaticum, (the com-
mon liver fluke), and of D. sinense^ D. crassum, and D. con-
junctum. In the last of these, as well as in D. sinense,
most of the details of the internal organization can be made
out through the thin transparent body-wall.

The Flukes pass through a complicated series of larval
changes, or metamorphoses, in the course of their develop-
ment, the larval stages, like the adult, being parasitic.

3. PLATYHELMINTHES OESTODA.

[Silcsbm 5EitU-£a0t 46].

The Cestoda, or Tape-worms, are Platyhelminthes
that also are parasitic in the alimentary canal of vertebrate
animals. Mouth and intestine are alike absent, the para-
site being nourished by simple absorption through its soft
body-wall.

A tape-worm such as Txnia solium, several good
specimens of which are exhibited in Case 46, consists of a
small head not much larger than a pin-head, followed by a
long chain of joints or segments, the anterior of which,
nearest the head, are very short, while the posterior in-
crease in length as they recede from the head.

The head is the real essential part of the animal : the
joints, or ''proglottides" as the yare called, are to be re-
garded as packets of egg-cells which are constantly drop-
ping off at the far end as the eggs ripen, and as constantly
being renewed by budding immediately behind the head.
This explains the fact that the segments nearest the head,
being the latest formed and youngest, are the smallest
while those farthest from the head, being the oldest and
most mature, are the largest.

The structure of the head is not easily seen without a
magnifying lens : it consists of a globular mass the apex of

4© A Guide to the Zoological Collections in the

which is slightly drawn out — the protuberance or " rosteh
lum" being armed with a ring of booklets — and the
equatorial circumference of which is furnished with four
large suckers. By careful examination all these details,
except only the individual booklets, can be recognized in
the exhibited specimens. It is by the booklets and suckers
that the parasite adheres to the wall of the alimentary
canal of its host. The structure of the segments or
"proglottides" cannot be made apparent to the naked
eye, and all that can be seen on simple inspection of a
large mature proglottis is that it is a flat solid oblong mass
with a prominent pore at the middle of one edge : this pore
is the genital orifice.

The proglottis, in fact, is honey-combed with reproduc-
tive organs — both elements, male and female, being pre-
sent in the same segment — and when it is fully mature it
is little more than a packet of impregnated ova. It will be
noticed that the pores are not all placed in one series
along the same side of the chain of segments, but in two
alternating series, on opposite sides.

A tape-worm goes through a complicated series of me-
tamorphoses in the course of its development from the egg.
The egg, after liberation from the proglottis, if it finds its
way into the stomach of a (vertebrate) " host " does not
forthwith develope into a tape-worm, but the resulting
embryo, which is furnished with booklets and somewhat
resembles in appearance the "head" of the adult tape-
worm, bores its way by means of its booklets through the
stomach of its host (first or intermediate host) until it falls
into one of the blood or lymph vessels, by the stream of
which it is carried often to some distant part of the body.
Somewhere or other in the tissues of its first or intermediate
host it lodges and, becoming encysted, is known as a
Cysticercus, or bladder-worm. The bladder-worm may
increase in size and may give rise by budding to other
generations of bladder-worms, but no further development
occurs within the first host. If, however, the first host be

Invertebrate Gallery of the Indian Museum. 41

eaten by another vertebrate animal, then the bladder-
worm, when it reaches the intestine of the second host,
develops into a sexually mature tape-worm such as those
exhibited.

A specimen of a Cysticercus^ or bladder- worm, is shown
in Case 46.

The Cestoda are further represented by three fine spe-
cimens of Taenia mediocanellata, which differs from T,
solium in being without the coronet of chitinous hooks.

4. PLATYHELMINTHES NEMERTINA. .

[(Lflllci5tern SLtiUl-rasij 46].

The Nemertina are flat worms, usually of small size, al-
though some reach gigantic dimensions, and are for the most
part marine : a few, however, live on land. Unfortunately
there are no specimens in the Museum collection, and we
are compelled for the present to represent the Order by en-
larged drawings of Tetrastemma agricola, a Land Nemertine
from Bermuda, and of Pelagonemertes rollestoni^2LX\. Oceanic
Nemertine, to both of which explanations are attached.
The Nemertina are the most highly organized of the
Platyhelminthes.

PHYLUM II OF THE CCELOMATA.

NEMATHELMINTHES.

[fficston MaU-fitse 46].
The Nemathehninthes or phylum of Non-segmented
Round-worms includes three natural groups: (i) the Ne-
matoda or Thread-worms, (2) the Chxtognatha, and {3)
the Acanthocephala. The most noticeable external char-
acter that they have in common is the elongated cylin-
drical body, which is devoid of appendages of any sort
and tapers more or less at both ends. The great majority
of the N emathelminthes are parasites : they are, however,
on a higher level than the PiatyhelmintheSy the body-
cavity being distinct. Reproduction is sexual.

42 A Guide to the Zoological Collections m the

I. NEMATHELMrNTHES NEMATODA.

[^.(Llcstcrtt cEall-cas£ 46].

The Nematoda or Thread-worms are mostly parasitic
either in the intestine or in the blood-vessels of vertebrate
animals. The Nematoda usually have a complicated de-
velopment, and pass through larval stages in the tissues
of one or more intermediate hosts before they reach their
final sexually-mature growth in a permanent host.

In the collection specimens of the following are exhibit-
ed : — Ascaris lumbricoides^ the common intestinal round-
worm, Ascaris from the intestine of the dugong, Trico-
cephalus dispar and Ankylostoma duodenale from the intes-
tine of man, and Filaria medinensis (the common guinea-
worm). The exhibited dissection of a large female of
Ascaris lumbricoides shows the nature of their internal
organization.

2. NEMATHELMINTHES CH>ETOGNATHA-

[SEcstern ®aU-ca0£ 46j.
The Chxtognatha include only the two genera Sagitta
and Spadella, small delicate worms found swimming free
at the surface of almost all seas. An enlarged drawing of
Sagitta is exhibited.

3. NEMATHELMINTHES AOANTHOCEPHALA.

[SJil^sttrn SEaU-ras£ 46].

The Acanthocephala include only the one genus Echin-
orhynchus, a parasitic round-worm, the head end of which
is armed with a thorny proboscis by means of which the
parasite maintains a firm hold on the wall of the gut of its
host. Like all parasites its organization is much degraded,
even a mouth and intestine being absent, the parasite as it
lies in the alimentary canal of its host being nourished by
simple absorption through the body-wall.

A slightly enlarged drawing of Echinorhynchus gigas is
shown in Case 46.

Invertebrate Gallery of the Indian Museum. 43

PHYLUM III OF THE CCELOMATA.

ANNELIDA.

[flSlcstcm (ilaU-rascs 43-44].

The next phylum is formed by the Annelida, including
the Sea-worms, the Earth-worms, the Leeches, and the
Wheel-animalcules, or Rotifera, The members of this
phylum usually possess blood and blood-vessels. In most
of the Annelida we distinguish very plainly the following
external characters :—(i) a body made up of a succession
of equal rings or segments, (ii) an anterior or head segment
behind which is the mouth, (iii) a posterior or anal segment
in which is the anus, (iv) ventral and dorsal surfaces, and
(v) bilateral symmetry.

The segments behind the head are not only alike exter-
nally, but internally their contents correspond or nearly
correspond, — each containing an equivalent portion at
least of digestive tube, of blood-vessel, of excretory organ,
and of nerve-cord.

In many Annelida each segment carries a pair of loco-
motor appendages, one on each side, which are known as
"parapodia" (or foot-like organs), and each parapodium
commonly consists of two elements — a dorsal element or
" notopodium " and a ventral element or " neuropodium,"
both carrying a tuft of bristles and a finger-like process or
"cirrus." This is especially well seen in the sections of
the large Sea-worm — Eunice.

The alimentary canal usually passes straight along the
body-cavity from one end to the other, and is held in place
by two longitudinal folds of the membrane that lines the
body-cavity — one above (the dorsal mesentery) the other
below (the ventral mesentery), and by transverse partitions
or "septa" which correspond to the segments. By these
septa the cavities of the segments are shut off from one
another.

44 ^ Guide to the Zoological Collections in the

The body-cavity contains blood, but there are also closed
blood-vessels, the two principal trunks of which traverse the
whole length of the body — one above (the dorsal blood-ves-
sel) and the other below (the ventral blood-vessel). When
"branchiae/' or gills, exist, as they do in most of the Sea-
worms, many small blood-vessels run into them, the
branchiae in short being organs specially developed for the
aeration of the blood. There are special excretory organs .
— a pair in each segment.

The nervous system consists of a cerebral ganglion placed
above the gullet, and connected, by means of a nerve-
rino- which embraces the gullet, with a pair of usually very
closely approximated jierve-cords that run along the ventral
wall of the body. This can be seen in one of the dissec-
tions of the Earth-worm in Case 44.

The internal morphological characters sketched above
can be seen by reference to the dissections of the large Sea-
worm Eunice from the Andamans, and by tne several dis-
sections of the common Earth-worm in Case 44. Repro-
duction is usually sexual, but many Annelida are reproduced
asexually by budding and fission from the parent.

The Annelida consist of three groups or natural Classes —
the Chsetopoda or Worms, the Rotifera or Wheel-animal-
cules, and the Hirudijiea or Leeches. Along with them we
may briefly consider, as an appendix, the Gephyrea or unseg-
mented Sea-worms, the Byyozoa or Polyzoa^ and the
Brachiopoda, which along with the Annelida, the Platyhel-
minthes and the Nemathelminthes used to constitute the
phylum Vermes of older systematists.

I. ANNELIDA CH/ETOPODA.

[SUcst^rn gSall-ras^s 43-44].

The Chsetopoda possess, on each segment, either paired
parapodia bearing cirri and setae and surmounted by breath-
ing organs (branchiae), or at least paired tufts of setae.

A head, often surrounded with tentacles, is generally
present.

Invertebrate Gallery of the Indian Museum. 45

The Chastopoda are divided into two great natural
Orders, (i) the /'c/y^^.s'^^ or segmented Sea-worms and (2)
the Oligochasta or segmented Earth-worms.

i. CH^TOPOBA POLYCH^TA.

Good typical examples of Polychaetous Annelida are
the large Sea-worm, Eunice, from the Andaman Reefs, and
the species of Nereis from Norway, in Case 43. In Nereis
we find a distinct head (formed of two segments, — " pros-
tomium " and " peristomium"), provided with tentacles,
palps or feelers, and eyes. On the under (ventral) surface
of the head is the mouth, from which, in one of the speci-
mens of Nereis pelagica, the muscular pharynx with its
chitinous hooks and its pair of large sickle-shaped chitinous
jaws is seen protruded.

Behind the head comes an indefinite number of equal
sized rings or segments, each of which bears, on each side, a
parapodium with dorsal and ventral cirri and bundles of
setae, while above the dorsal half-section of each parapodium
(notopodium) is abroad fiat membranous plate — the gill-
plate or branchia, by means of which the blood is aerated.
On the ventral surface of each segment are seen the depres-
sions where the excretory organs (" segmental organs"),
of which there is a pair in each segment, open.

The last segment is smaller than any of the others, and
in the middle of it is seen the anus with a pair of long anal
cirri.

The main facts of the internal organization of the typi-
cal Polychxta can be made out from the lettered dissec-
tions and sections of Eunice from the Andamans, exhibited
in Case 43.

The bundles of setae, both ventral and dorsal, and the
gill-tufts which surmount the latter, are remarkably well
shown in the specimens of Chloeia.

The Seaworms are sub-divided into two groups accord-
ing to their mode of life, namely the Errantia or free-

46 A Guide to the Zoological Collections in the

swimming Polychxta^ and the Tuhicola or sedentary Poly-
chseta.

POLYCH/ETA ERRANTfA.

The Errantia, or free-swimmers, live usually in sand and
mud and shallow water near the coast: some, however, in-
habit the abyssal depths, and some live habitually at the
surface of the ocean. In accordance with their manner
of life they have a distinct head with powerful biting jaws
(well seen in Eunice), and have well-developed parapodia
and setae for locomotion, and usually large and numerous
branchiae or breathing organs. Although freely locomo-
tive they sometimes inhabit thin tubes, as may be seen in
Hyalincecia.

POLYCH/ETA TUBICOLA.

The Tuhicola or sedentary Sea-worms live in protective
tubes or shells, which they either manufacture, or actually
secrete for themselves. The tubes may consist of grains
of Pand and stones and broken shells glued together by a
sticky secretion, or of chitin strengthened with sand, etc.,
or of carbonate of lime. Examples of these different tubes
are exhibited in Case 43.

Being sedentary, the Tuhicola have no need of para-
podia and setae for locomotion, and these structures there-
fore along with branchiae are quite rudimentary. The
head is indistinctly demarcated from the rest of the body,
and there are no jaws. On the other hand the anterior
end of the body, which can be protruded from the tube, is
provided with bundles of long thread-like tentacles which
are not only used for sweeping food into the mouth, but
are also organs of respiration.

These tentacles are beautifully shown in the exhibited
specimens of Cirratulus filigerus and Spirographis
spallanzani from the Gulf of Naples.

In the exhibited collection the Polychaeta are repre-
sented by specimens of the following genera from Indian
seas : —

Errantia — Chloeia, Eurythoc^ Aphrodita, Eupompe,

Invertebrate Gallery of the Indian Museum. 47

Eunice^ Hyalincecia, the last named from the
depths of the Arabian Sea.
Tubicola — Branchiomma, Chstopterus, and Serpula,
the last named also being from the deep-sea.
Besides the Indian representatives of the
Order there is exhibited a fine collection of
beautifully-prepared spirit specimens from the
Naples Aquarium, and in Case 47 are some
glass models.

ii. CH^TOPODA OLIGOCH^TA.

The other order of the Annelida Chxtopoda is formed
by the OUgochseta, and includes the Earth-worms and
River-worms.

These much resemble the Polychaeta in that they have
a cylindrical body made up of rings or segments, but they
differ from the Polychxta in several inportant characters.
In the first place they have no definitely demarcated head
with palps and tentacles, and in the second place the seg-
ments of which the body consists never bear parapodia
and branchiae and have but few setae and these small.

The details of the internal organization of a typical
Oligochaete — the common Earth-worm — are displayed in a
series of dissections in spirit in Case 44 to which explana-
tory drawings are attached.

2. ANNELIDA ROTIFERA.

The Rotifera or Wheel-animalcules are aquatic animals
of such microscopic size as to be beyond the limits of an
exhibition gallery, except in the form of greatly magnified
drawings.

Though externally but little resembling adult worms
they have many essential characters in common with the
larval annelid type.

The sexes are separate, and only the females attain
their full organization, the males being small, being devoid

48 A Guide to the Zoological Collections in the

of an alimentary canal, and leading therefore only a tran-
sient life.

An enlarged diagrammatic drawing of a female Rotifer,
in side view, is exhibited in Case 44-

3. ANNELIDA HiRUDINEA-

[® est cm SEaU-rasc 44].

The third class of the Annelida includes the Hirndinea
or Leeches.

Ihe Leeches, like the Earth-worms, have a ringed and
segmented body; the rings however are only external
markings and must not be confounded with the " segments",
for each segment consist of five rings. The segments of
the Leeches differ from those of the other Annelids in being
destitute of appendages (parapodia and setae) of any kind.
Locomotion is effected entirely by suckers, of which there
are usually two, one at the fore end and one at the after
end of the body. In the anterior sucker lies the mouth,
which in some leeches is provided with three jaws disposed
in Y-fashion and each armed with a saw-like series of
chitinous teeth.

The nature of the internal organization of the Leeches
is shown in the spirit dissections of the large Horse leech,
in Case 44, alongside of which is an explanatory drawing.
Of the Leeches a few are marine, but the greater number
live either in freshwater or in damp places on land. The
marine Leeches are represented in the collection by fine
specimens of Pontohdella from the European seas. The
terrestrial leeches are represented by the following genera
from India : — Hirudo, Hsemodipsa^ and Lininatis.

The habits of the leech are proverbial.

APPENDIX TO THE PHYLUM
ANNELIDA.

As an appendix to the Annelida we may here consider
the Gephyrea, the Brachiopoda, and the Polyzoa^ three

Invertebrate Gallery of the Indian Museum. 49

groups which have been classed together by Professor Ray
Lankester as a distinct phylum under the name of Pod-
ax onia.

The reasons why these three groups have been placed
together near to the Annelida group cannot be discussed
here, where it is enough to say that they follow from the
fact that the larval forms of all four groups have many
characters in common.

I. GEPHYREA.

[®e0tern giJitU-fa0e 44].

The Gephyrea, or Spoon-worms, are entirely marine.
They differ from the Chxtopoda in not having the body
segmented and in not having parapodia and setse.
Sipunculus, of which several specimens are exhibited in
Case 44, illustrates this class.

In Sipunculus we see a papillated proboscis, at the end
of which is the mouth-opening. The rest of the body is
marked by deep longitudinal and transverse furrows, the
latter dividing the body into a series of rings which, how-
ever, are only superficial and must not be confounded with
the segments of Annelids.

In the Indian Seas Sipunculus has been found on the
Andaman reefs and in the depths of the Andaman and
the Laccadive Seas.

The details of the internal anatomy of Sipunculus can
be seen in the dissected specimen, which has been laid
open along the ventral surface, a little to the right of the
middle line of the body. The dissection is accompanied
by an explanatory drawing.

2. BRACHIOPODA.

[SEestan eUaU-nis^s 44-45].
The body of the Brachiopoda is enclosed in a bivalve
shell, something like the shell of a Mussel or of a Cockle in
external appearance, and so far as mere outward resem-
blance goes the adult Brachiopoda have little likeness to

D

5o A Guide to the Zoological Collections in the

worms, near which, however, they are classed on embryolo-
gical grounds.

The Brachiopod shell consists of an upper or dorsal
and a lower or ventral valve, and, as may be observed in the
specimens of Lingula anatina, is furnished at its hinder
end with a long fleshy stalk, or " peduncle ", by which the
animal is fixed to the sea-bottom. In Lingula the ''pedun-
cle " simply passes out between the valves : in Waldhei-
mia it passes through an aperture in the beak of the ven-
tral shell. In a few forms the "peduncle" is wanting.

A general idea of the internal organisation of the Bra^
chiopoda may be gained by a study of the lettered dissec-
tions of Lingula anatina. In Lingula the inner surface
of each valve is seen to be lined by a thickened fold
of the integument — the " mantle '\ the edge of the mantle
lobes being closely fringed with "setae". A large part
of the space between the "mantle" folds is occupied
by the coils of two long fringed " arms " — one situated
on each side of the mouth — which function both for
procuring food and as organs of respiration. At the
broad fore-end of the shell is the mouth lying between the
coiled up arms, and behind it the coiled intestine, embedded
in a dark brown granular mass, — the liver. The rest of the
cavity is filled by the great muscles which open and close
the shell.

The Brachiopoda are all marine : they are but sparely
represented at the present day, the majority of known
species being fossils, many of them of great geological
antiquity.

The Brachiopoda are divided into two groups — the
Ecardines^ represented by Lingula^ in which the shell is
not hinged and not furnished with an internal calcareous
hoop for the support of the long coiled " arms ", and the
Testicardines, represented by Waldheimia, in which the
shell is hinged and furnished with an internal calcareous
hoop for the support of the " arms ".

In the collection the only representatives from the
Indian seas are Lingula and Crania from comparatively

Invertebrate Gallery of the Indian Museum, 51

shallow water, and Terebratula from the depths of the
Laccadive Sea ; but Australian, Mediterranean, and Atlan-
tic forms are well represented.

3. POLYZOA.

[®e0hm ®JaU-i:a0C0 44-45].

The Polyzoa are small animals which bud asexually,
like many of the Hydrozoa and Actinozoa, to form branch-
ing or encrusting shrub-like or moss-like colonies. Some
live in freshwater, but the majority are marine. The
colonies are supported and protected by a horny (chitinous)
or calcareous exoskeleton formed by the hardening of
the outer layer of the ectoderm of their units or zooids.
It is these horny and seaweed-like, or calcareous and
coral-like, exoskeletons, denuded of their occupants, which
form the majority of museum specimens of Polyzoa.

A good example of a Polyzoon colony is the specimen of
Retepora in Case 45. This is seen to be an encrusting
branching lichen-like mass, the thin leaves of which are
formed of carbonate of lime and have the texture of a very
fine lace with very regular meshes. The meshes of the
lace-work are the openings of chambers which, during
life, were occupied by the Polyzoa zooids. The colony,
in short, consists of myriads of these little chambers, all
shut off from one another, in each of which dwelt a small
animal, or zooid, of the shape and structure shown in the
enlarged diagrammatic drawing alongside of the specimen ;
and each little chamber was formed simply by the calcifica-
tion of the cuticle of its occupant. During life the zooids
ordinarily extrude their head and tentacles from the open-
ings of the chambers, as shown in fig. i, but they are able,
when alarmed, to completely withdraw within the cham-
bers, and sometimes to close the orifice, as shown in fig. 2.

In many of the Polyzoa colonies a division of physiolo-
gical labour occurs, with the result that some of the zooids
lose all resemblance to the typical form. Certain of them
become transformed into structures resembling a bird's
head, and these, which are known as avicularia and are

D 2

52 A Guide to the Zoological Collections in the

shown (enlarged) in fig. 3, by a continual snapping action
seize and hold the animalcules that form the prey of the
colony. Others become transformed into long lashlike
filaments, known as vibracula (fig. 4), which also serve
the colony by sweeping prey into the mouths of the ordi-
nary zooids.

The Polysoa of the Indian Seas have not as yet been
systematically investigated. Many of them appear to be
identical with well-known European forms, a fact that is
easily explained when it is remembered that Polyzoahahi'
tually encrust the bottoms of ships, and are thus likely to
be widely distributed along frequented lines of navigation.

In the exhibited collection of Indian Polyzoa specimens
of the following genera are included : — Cellularia, Rete-
pora, and Cellepora.

As already stated, the majority of the Polyzoa are
marine. They incrust rocks, dead coral, etc., and thus
contribute considerably to the growth of reefs. They also
incrust all sorts of floating drift. The larvae are free-swim-
ming.

PHYLUM IV OF THE CCELOMATA.

ARTHROPODA.

[(Ea0£0 37—42 nlong <i;orlhertt toali, 48—63 alotts acsUrn
toaU, 64—69 along Southern toali, aitl) ^^©k-ras^s
70-125].
The great phylum of the Arthropoda includes the re-
markable form Peripatus^ the Myriapoda (Centipedes),
the Hexapoda (Insects), the Crust acea,2.Vi^ the Arachnida
(Spiders and Scorpions). It contains an immense number
of species, far more in short than all the species of all
the other phyla put together.

In their general plan of structure the Arthropoda re-
semble the Annelida proper, and the main groups of the

Invertebrate Gallery of the Indian Museum. 53

latter phylum, namely the Rotifera and Cha^topoda, have
been classed with the Arthropoda by Professor Ray Lan-
kester as a snigle phylum under the name Appendicu-
lata ; the two phyla resemble each other in the prime
fact that they are alike made up of a repetition of rings
or segments (somites), but whereas in the Annelida the
segments, with the exception of the two which form the
head and the one which forms the posterior limit, are all
very nearly alike and equivalent in function and structure,
in most of the Arthropoda the segments differ in function,
and consequently in structure, in the different regions of
the body. Instead of a body constructed of a succession
of nearly similar rings or segments, we now find in the adult
Arthropod, a body in which the segments usually fall into
three dissimilar groups or regions — a head region, a thorax
region, and an abdominal region — and even within the limits
of any one region, but especially in the regions of the
head and thorax, the constituent segments may differ from
each other. Another important morphological difference
between the Annelida and the Arthropoda is that in the
Annelida the segmental (locomotor) appendages, when they
exist, are unjointed, whereas in the Arthropoda these ap-
pendages, or limbs, are built up of a succession of different
pieces all movably jointed together — from which fact the
name Arthropoda is derived, viz., "joint-footed" animals,
or animals with jointed legs. A third less important and
less constant difference, which relates to the manner of
life, is that the Annelida usually have soft bodies, while the
body and limbs of the adult Arthropod are generally
encased in an armour of chitin.

The head region of the Arthropod consists of several
segments which are often fused together, their appendages
being modified to form sensory organs (or antennae), and
biting and chewing organs (or mandibles and maxillae).

The thorax region, which lies behind the head and is
often fused with it to form a cephalothorax, also consists
of several intimately fused segments, the appendages of

54 -^ Guide to the Zoological Collections in the

which usually preserve their purely locomotor function and
structure, but are sometimes modified for prehension, and
even for the mastication of food.

The abdominal region forms the posterior part of the
body and consists of numerous segments, which are but
little modified in form, and are in some groups {e.g., the
Insects and Spiders and some Crustacea), quite devoid of
appendages.

The alimentary canal has very much the same general
form that it has in the Annelida^ as has also the nervous
system ; and this can be verified by inspection of the letter-
ed dissectio ns in Case 54, which is occupied entirely by
preparations illustrating the internal morphology of the
Arthropoda. The nervous system of the Arthropod is,
however, much more highly developed, and sense-organs
(feelers or antennae, eyes, olfactory and auditory organs)
are usually present. The breathing organs differ greatly
in the different groups : in Peripatus, in the Centipedes,
and in the Insects, air is taken in through numerous small
tubes, known as tracheae, which open to the exterior at
various places on the surface and ramify throughout the
tissues of the body : in the Spiders air usually passes in
and out of pocket-like depressions known as pulmonary
sacks : in the Crustacea breathing is effected by means of
gills. The different forms of breathing organs — tracheae,
pulmonary sacks and gills — are specially shown in several
preparations in Cases 54, 60, 62 and 63.

The blood, which is colourless, commonly circulates in
a distinct system of blood-vessels, and is often propelled
by a contractile heart which is placed in the dorsal half of
the body, as is shown in the dissection of the common Crab,
and common freshwater Shrimp in Case 54.

Reproduction is usually sexual, but many forms of
asexual reproduction occur among the Arthropoda, espe-
cially in the Class of Insects.

Invertebrate Gallery of the Indian Museum. 55

I, ARTHROPODA CRUSTACEA.

\(^mt% 37—42 northern txxis 48-55 SEcston toali, anb
64—69 (Southern enb].

The Crustacea are Arthropods that breathe by means
of gills.

A majority of them live in the sea, but many species
inhabit fresh-water, and some live on land.

The ringed or segmented nature of the body is gener-
ally very apparent, and most of the rings or segments
carry a pair of jointed appendages which are variously
modified in different regions of the body for feeling, for
biting and chewing, for prehension, for crawling, and for
swimming.

A good general idea of the external structure of a
typical Crustacean can be gained by examining the large
Prawn in Case 49, in which all the segments of which the
body is made up are, as far as is possible, disjointed from
one another, and laid out in succession with their ap-
pendages. The Crustacea are usually encased in a stout
" sheir, or exoskeleton, formed by the hardening of the
superficial layer of the integument : this shell is periodically
cast off or moulted en masse, to be again soon renewed.

In many, or in most, Crustacea the main develop-
mental changes, instead of being completed within the
^§&j are continued long after the young one has left the
egg and has started an independent life, the final form
being reached only after a succession of moults or " meta-
morphoses" : so that the young when first hatched is quite
unlike the adult.

The Crustacea fall into two divisions — the Entojuo-
straca which are for the most part small lowly organised
aquatic species, with a body made up of an inconstant
number of segments or somites ; and the Malacostraca
which are for the most part large, highly-organised species,
both aquatic and terrestrial, with a body made up of a
constant definite number of somites, each one usually with

56 A Guide to the Zoological Collections in the

its pair of appendages. The curious form Nebalia is a
link between these two divisions.

a. CRUSTACEA ENTOMOSTRACA.

[aac0tern GEitU-rii0£ 48],

As the Entomostfaca are for the most part minute,
and can be properly examined only under the microscope,
they occupy but an unimportant place in the Museum
Gallery and cannot, therefore, be treated of at any length
here.

There are four orders of the Entomostraca — namely,
the Phyllopoda, the Osiracoda, the Copepoda^ and the
Cirripedia.

The species which constitute the three first-named of
these orders are almost all too minute for exhibition.

. i. CRUSTACEA ENTOMOSTRACA PHYLLOPODA.

The Phyllopoda are represented in Case 48, by two
species of Apus from Europe.

In Apus the body is made up of a large number of
ring-like segments, the first twenty or more of which are
covered over dorsally by a large shield-shaped carapace,
and bear each a pair of bilobed leaf-like feet ; while the
last five or six are uncovered and are devoid of append-
ages, and project behind in the form of a short ringed
cylindrical tail which ends in a long fork. At the front
of the carapace are seen the large eyes.

ii. CRUSTACEA ENTOMOSTRACA OSTRACODA.
The Ostracoda are marine forms usually of a size far
too small for exhibition. To illustrate their size some
specimens of Cypridina are shown in Case 48.

iii. CRUSTACEA ENTOMOSTRACA COPEPODA.
The Copepoda inhabit both salt-water and fresh-water,
and they also are for the most part toos mall for exhibi-

Invertebrate Gallery of the Indian Museum. 57

tion. Some of them live as parasites on fishes, and one
of these parasitic forms is exhibited, with the front end of
its body embedded in the tissues of its host, — a fish of
the genus Macrurus. It must be remembered, however,
that this species, being a parasite, has undergone great
degeneration and has retrograded greatly from the typi-
cal Copepod form. A more typical form is Cyclops shown
in Case 48.

iv. CRUSTACEA ENTOMOSTRACA CIRRIPEDIA.

The Cirrtpedia are well known to sea-farers as Acorn-
shells and Barnacles, and in external appearance are quite
unlike Crustaceans, being commonly enclosed in a multi-
valve calcareous shell, somewhat resembling that of a
Mussel, which is fixed to foreign objects, often by means
of a long fleshy stalk. It is by following out their de-
velopmental changes that their Crustacean affinities are
clearly proved, for the young, or larval, Cirriped, far
from being fixed, is freely locomotive, and in all important
particulars resembles the early larval form of the Prawn :
it has eyes, antennae, and swimming-feet, but with increas-
ing growth it fixes itself by means of its antennae and by
a substance secreted by certain glands, known as cement-
glands, which open at the base of the antennae : after
attachment it loses its eyes, antennal filaments, and
swimming.feet, and developes forked cirriform feet and
an external shell. The adult Cirriped is thus immovably
fixed, head and mouth downwards, with its forked cirri-
form feet protruding between the valves of the shell
behind, the feet being used to sweep currents of water
containing food and oxygen towards the mouth.

The internal structure of a typical Cirriped can be seen
from the dissections of Scalpellum in Case 48.

A few of the Cirripedia are parasitic. One of these
parasitic forms is shown in the specimen of Sacculina
parasitic on the abdomen of a crab. Sacculina, as a re-
sult of its parasitic habits, has retrograded to such an

58 A Guide to the Zoological Collections in the

extent as to have lost all resemblance, not only to its
Crustacean relatives, but to an animal of any sort, — all its
organs, except its genital glands, have degenerated and
atrophied, and in its final stage it is, as the exhibited
specimen shows, a mere shapeless bag of eggs.

The sexes in the Cirripedia are commonly united iu
the same individual, but in some genera, of which Scal-
pellum is one, there are also what are called "comple-
mental males " which attach themselves like parasites to
the hermaphrodites. One of these small parasitic comple-
mental males is seen in one of the exhibited dissections of
Scalpellum,

The Cirripedia are represented in Case 48 by Scalpel-
lum and Verruca from the depths of the Andaman Sea and
by Lepas and Conchoderma from the German Ocean.

b. CRUSTACEA MALACOSTRACA.

[Qrii0£0 37-42, 49-55, hi, 59, 64-69].

There are six orders of Malacostracous Crustaceans —
Amphipoda, Isopoda, Cumacea, Stomapoda, Schizopoda,
and Decapoda — all of which are represented in the exhi-
bited collection.

In the Malacostraca the body consists typically of 2 \
segments, all of which, except the last, bear a pair of jointed
limbs. From these 21 segments, however, some zoolo-
gists exclude the segment that bears the eyes, and others
exclude the terminal limbless segment or telson — thus re-
ducing the number to 20, or to 19.

Of these 21 segments six are always immovably fused
together to form a head, the limbs or appendages of which
are known in order from before backwards as eye-stalks,
antennules, antennae, mandibles, first maxillae, and second
maxillae. Of the remaining 15 segments eight form the
thorax and are often more or less fused together and to
the head to form a cephalothorax, and their limbs or
appendages are modified to form foot-jaws and prehensile
(often pincer-like), or walking, or rarely swimming, legs :

Invertebrate Gallery of the Indian Museum. 59

there are usually three pairs of foot-jaws or maxillipeds,
and five pairs of legs. The last seven segments (abdo-
minal segments) are almost always separate and distinct,
and all but the terminal one usually carry a pair of swim-
ming or jumping feet : the terminal limbless segment is
known as the "telson."

Gills are borne on either the thoracic or the abdominal
limbs.

The nature and typical arrangement of the segments,
and of their appendages, should be studied in the disarti-
culated specimens of Nephrops, Pensus, Scylla, Cenobita,
and Squilla, in Case 49.

i. CRUSTACEA MALACOSTRACA AMPHIPODA.

[®£0t£rn cSlaU-ra0^ 50].

The Amphipoda are usually very small Crustaceans, and
are not therefore adapted for exhibition in the Gallery.
Some of the deep-sea species, however, are comparatively
gigantic, and a specimen of one of these — Andania,
dredged in the Bay of Bengal at a depth of 1,997 fathoms
— is exhibited in Case 50.

Some of the Amphipoda live in freshwater, but the
great majority are marine. In the Amphipoda the eyes
are never stalked. Of the thoracic segments seven are
almost always separate and distinct from one another and
from the head.

The nature of the Amphipod body should be studied in
Andania.

1 he following genera from Indian waters are exhibited : —
Andania, Rhabdosoma^ Caprcila, besides a few species
from Europe and New Zealand.

ii. CRUSTACEA MALACOSTRACA ISOPODA.

[5Ec0t£nt cSlaU-rasc 50].
The Isopoda include the familiar Woodlice, and are
small Crustaceans, some of which inhabit dry land and some

6o A Guide to the Zoological Collections in the

fresh- water, but the majority of which are marine. A
good many of the marine species are parasites and are
more or less degraded in form.

The Isopoda are usually small, but one of the deep-sea
species — Bathynomus giganteus, two specimens of which
are exhibited in Case 50, is of relatively gigantic propor-
tions, one of the exhibited specimens being over eight
inches long.

Particular attention should be paid to these magnificent
specimens of Bathynomus, as they exhibit on such a
unique scale the typical form of the body and appendages
of the Isopoda, showing (i) a head made up of six
(five) segments fused together to form a single ring and
bearing a pair of sessile eyes, a pair of short antennules, a
pair of longer antennae, a pair of mandibles, and two pairs of
maxillae; (2) a thorax of eight segments, the first of which,
bearing a pair of foot -jaws, is fused with the head, while
the remaining seven are separate and distinct rings, each
of which carries a pair of many-jointed crawling legs ; and
{3) an abdomen made up of seven segments, the first five
of which are separate and carry each a pair of broad mem-
branous bilobed paddles, while the last two are fused
together to form a broad telson with a single pair of two-
bladed swimming paddles : upon each lobe of each of the
first five pairs of abdominal appendages can be seen a
branching feathery gill.

Besides Bathynomus the following Indian genera are
represented in the exhibited collection : — Cymothoa, Cerat-
othoa, Nerocila, Anilocra, Idotxa^ Cleantis, Ligia,
Bopyrus, and Armadillo, the last being a terrestrial
species.

Bopyrus is parasitic in the gill-chamber of prawns, and
the males are of minute size and further attach themselves
as parasites to the abdomen of the female. This is well
seen in the two exhibited specimens, in one of which the
tiny male is shown alongside the female, while in the other
the male is seen attached in its natural position.

Invertebrate Gallery of the Indian Museum. 6i

In addition to the above there is exhibited a handsome
specimen oi Arcturus cornutus, Beddard, from the depths
of the Andaman Sea.

iii. CRUSTACEA MALACOSTRACA CUMACEA.

[ffl;i^0tn-n ®aU-r!t0e 54].
The Cumacea is a small order of small Crustacea which
have a resemblance to some of the larval forms of the
Decapoda.

This very limited order is represented in the Gallery
by a small specimen of Diastylis from Norway.

Alongside of this specimen are shown for comparison
some larvae of a prawn {Penxus) in the Mysis stage.

iv. CRUSTACEA MALACOSTRACA STOMAPODA.

[»C0t£m ffltnll-fit0C0 49 anb 52],

In the Stomapoda the abdominal region is greatly de-
veloped, forming a powerful swimming " tail", its append-
ages having the form of broad two-bladed swimming
plates.

The segmental structure of this Order is so well dis-
played in the large dissected specimen of 5'^z<;///rt raphidea^
in Case 49, that no further explanation is here required.
Observe that the first five pairs of thoracic limbs form
powerful chelate foot-jaws, those of the second pair being
of predominant size and being used for seizing and hold-
ing prey.

In the spirit specimens observe the feathery gill-tufts
on the abdominal swimming plates.

The Stomapoda are all marine, and are specially abun-
dant in the seas of the tropics : they are excessively pre-
daceous, seizing their prey with the second pair of thoracic
limbs, which on account of their great size and terrible
armature are known as the raptorial claws.

62 A Guide to the Zoological Collections in the

In their growth thsy pass through several metamor-
phoses, and even the later larval stages differ so much
from the adult that they were originally taken to belong
to a different genus, one of which was described as Erich-
thus. Several specimens of Squilla in the Erichthus stage
are exhibited.

The Stomapoda are represented by specimens of the
following genera : — Squilla, Lysiosquilla, Chloridella,
Pseudosquilla, Protosquilla, Gonodactylus.

V. CRUSTACEA MALACOSTRACA SCHIZOPODA.
[ffl;c0U rn md\-t&Qt 54].

The Schisopoda have a complete outward resemblance
to prawns, but they differ from the prawns and their re-
latives in the form of the thoracic limbs, all of which are
forked from near the base — hence the name of Schizopoda
or cloven-footed Crustaceans.

The Schizopoda are mostly small, but some of the
deep-sea forms are as large as a small prawn. In the
exhibited collection they are represented by fine speci-
mens of Gnathophausia and Eucopia from the depths of
the Bay of Bengal.

In Gnathophausia the external structure of the Schizo-
pod body can be very well seen.

vi. CRUSTACEA MALACOSTRACA DECAPODA.

[Oraees 37-42, 49. 51. 53. 55. 64-69].

The Decapod Crustaceans include the two great groups
of the Lobsters and Crabs, along with a third intermediate
group typified by the Hermit-crabs.

All three groups are essentially alike in structure, and
the chief distinction between them is to be found in
the relative size and functional importance of the abdomen.
In the Lobsters the abdomen is as well developed as any
other region of the body, and forms a .powerful symmet-

Invertebrate Gallery of the Indian Museum. 63

rical swimming "tail": in the Crabs the abdomen is
rudimentary, is carried tucked up out of sight beneath
the thorax, and lodges only the hinder end of the intes-
tine : while in the Hermit-crabs the abdomen is in an
intermediate condition, being useless as an organ of locomo-
tion, asymmetrical, soft, and liable to injury, but being of
considerable size, and lodging several important organs.

In all the Decapod Crustacea the body is made up of
twenty-one segments, if we include the region that carries
the eye-stalks and the telson as such, and the first fourteen
are almost always immovably fused together to form a
cephalothorax, the back of which is known as the carapace,
and the sides of which are expanded outwards and down-
wards to form a gill-chamber. Of the paired appendages
of these fourteen segments, the first are eyes borne on long
stalks, the second are antennules fringed with hairs which
are probably organs of smell (also in the base of the
antennules the organ of hearing is lodged), the third are
long antennae or feelers, the fourth are mandibles or bit-
ing-jaws, the next five pairs are closely crowded together
on each side of the mouth and are modified to form chew-
ing-jaws, or maxillae and maxillipeds, while the last five
are many-jointed crawling feet, some or all of which may
end in powerful nippers, or chelae. The first pair of thoracic
legs usually end in nippers of great size and are known as
"chelipeds". In a few forms the one or two last pairs of
crawling legs are rudimentary or absent.

The abdomen consists of seven segments, the structure
of which will be subsequently considered.

In connexion with the appendages the breathing-organs,
or gills, must be noticed : they are sometimes feather-like,
but much more commonly brush-like structures attached
to or near to the bases of a certain number of the thoracic
appendages on each side, and enclosed in a gill-chamber
formed by the lateral extensions of the carapace already
mentioned. The water with its dissolved oxygen usually
passes into the gill-chamber from behind, and after bath-

64 y^ Guide to the Zoological Collections in the

ing the gills and giving up its oxygen, passes out at the
fore end of the chamber, a continuous current from behind
forwards being kept up not merely by the movements of
the legs but by a special " baling-out scoop " or scapho-
gnathite, attached to the second pair of maxillse. Similar
baling and sweeping organs are often attached to the
maxillipeds, as is well seen in the disarticulated specimen
of the crab Scylla serrata. The nature and arrangement
of the gills as well as of the digestive system, of the
circulatory system (heart, etc.), and of the nervous system,
should be observed in the dissected spirit specimens
of Scylla, Palaemon, Palinurus, Pendens and Nephropsis,
in Case 54, in which is also shown the stomach of a large
crab laid open to display the gastric teeth and gastr'"
hairs.

a, DECAPODA MACRURA.

[Qrit0cs 37-41, 49. 53. 55].

This sub-Order includes the Shrimps, Prawns, Lobsters,
Crayfish, etc.

For a general idea of the structure of a typical macrur-
ous or long-tailed Decapod Crustacean, the disarticulated
specimen of one of the common Indian prawns {Penscus
indicus) in Case 49 should be studied.

Comparing this with the specimen of the common
Indian edible crab {Scylla serrata) alongside, we find
that the Prawn differs from the Crab in having a long and
large abdomen or " tail ", every segment of which, except
the last, carries a pair of swimming-legs, and that the legs
of the last segment but one are expanded to form with
the last and legless segment a powerful fin or " swim-
meret."

Other differences easy to notice are that the third pair
of foot-jaws or maxillipeds in the Prawn are slender and
claw-like, and that the carapace is prolonged anteriorly
into a long pointed "rostrum."

Invertebrate Gallery of the Indian Museum. 65

The Macrurous Decapods form a large sub-Order, most
of the members of which are marine, though a consider-
able number inhabit rivers and other fresh-waters.

The marine forms are found in every kind of region,
from the Arctic shores to those of the Equator, from tide-
mark to the deepest abysses, from creeks and backwaters
to the open expanses of the ocean ; and they are found in
all situations, burrowing in the sand and mud, hiding in
crevices in rocks and under stones, sheltering amid branch-
ing colonies of the Sea-firs, Sea-mats, etc., flitting near the
surface of the ocean, or swarming near the bottom.

Of the numerous tribes and families into which the
Decapod Macrura are subdivided, the following are re-
presented in the Gallery : —

1st Tribe, Thalassinidea, Case 41. — Two families are re-
presented, the Thalassiniclx and the Callianassida;.

The Thalasslnidse include the single genus Thalassina,
one of the few species of which, Thalassina scorpionoides,
is common in Indian estuaries, where it lives in deep
burrows tunnelled in the mud. Observe the long narrow
tail already beginning to show signs of degeneration, and
the small degenerated eyes.

The Callianassidse are small burrowing Crustaceans
found in the sand usually between tide-marks, but often
at great depths. Specimens of Callianassa, Callianidea
Gebia, and Gebiopsis are shown in the Gallery, all of them
having been taken in Indian waters. In both of these
families the carapace is short and the *' tail " long, and
the pincers of the thoracic legs are imperfectly developed,
forming '' subchelae."

2nd Tribe, Scyllaridea or Loricata, Cases 41 and 53.

This tribe includes two families, the Scyllarida; and the
Palinurid.v, both of which are represented in the Gallery.

The Scyllaridse have a broad flattened crab-like cara-
pace, and the antennae (second pair) form flat warty plates.
None of the thoracic legs are in the form of pincers or

66 A Guide to the Zoological Collections in the

chelae, but all end in simple claws. Three genera are met
with in Indian Seas — Scyllarus, Themis, and Ibacus,
specimens of all of which are to be seen in Cases 41
and 53.

The Paiinuridae much resemble Lobsters at first sight,
but they differ from the Lobster in not having chelae, — all
the thoracic legs ending in simple claws. One genus, or
subgenus, Panulirus is very common in Indian Seas, off
rocky coasts, and in the neighbourhood of coral islands.
Notice the specimen of Palinnrus {Panulirus) ornatus
with one side of the carapace removed to display the gills,
(Case 54).

3rd Tribe, Astacidea, Case 40. — This tribe includes the
Lobsters, and contains four families, all of which are re-
presented in the Gallery, though only two, the Eryontidx
and Nephropsidx, are to be met with in Indian Seas.

The recent Eryontidae are entirely confined to the great
depths of the sea : the carapace is depressed, and in cor-
relation with the fact that they live at great depths to which'
sunlight cannot penetrate, the eyes are rudimentary or
absent : except in the males of one genus all the thoracic
legs end in chelae. In the Indian Seas the Eryontidx ap-
pear to be fairly common at depths of from 500 to 1,500
fathoms. Specimens of three genera Polycheles, Penta-
cheleSy and Willemcesia, are exhibited, all of which were
dredged by the officers of the Indian Marine Survey.

The Nephropsidae or Lobsters proper, are, as far as the
Indian fauna is concerned, to be found only in deep water
(175 to 250 fathoms), although in other regions they occur
in shallow water. The Indian genera are Nephrops and
NephropsiSy fine specimens of which are exhibited along
with Lobsters from the European and Japan Seas. In
Nephrops the eyes are of enormous size, while in Nephr op-
sis they are the merest rudiments. This contrast illus-
trates the fact that when animals live at moderate depths
to which a certain amount of sunlight can penetrate, their
eyes often become increased in size to profit by all the

Invertebrate Gallery of the Indian Museum. 67

light that exists ; but when they live at great depths to
which no sunlight penetrates, their eyes, being then of
little or no use, often become atrophied.

The fresh-water Lobsters, or Crayfish do not occur in
India, and all the exhibited specimens of these two families
come from Europe and Australia.

4th Tribe, Penaeidea, Case 39.— This tribe includes the
Prawns and contains, two families, the Sergestida; and
the Penaeidse.

In the Sergestidge the fourth and fifth pairs of thoracic
legs are rudimentary or absent. Sergestes is the only
genus of the family represented in the Gallery, the speci-
mens having been taken at great depths in the open part
of the Bay of Bengal.

The Penaeldse foriji a very large family, the members
of which have the abdomen very long and well adapted
for swimming : very commonly the first three pairs of
thoracic legs end in pincers. The female does not carry
her eggs about with her when laid. Many Penxidse are
gregarious, living in swarms at the bottom of the sea : such
is the case with Penxus, Solenocera, and Aristxiis. The
Penxidx are very well represented by numerous specimens
of the following genera, all from the Indian Seas — Stenopus,
Penseus^ Crotalocaris, Aristseus^ Aristasopsis Gennadas
Hemipenxus^ Hymenopenanis, Metapenseus, Haliporus
and Solenocera. Some species of the deep-sea genus
Aristccus are brilliantly luminous.

5th Tribe, Carldea, Cases 37 and 38. — This great tribe in-
cludes the Shrimps and " fresh-water Prawns," and con-
tains a very great variety of forms, which have been
arranged in a great number of families.

In the Caridea there are never more than two pairs of
pincer-like thoracic legs, and the eggs when laid are
usually carried about by the female, attached to her ab-
dominal swimming-legs, until they are hatched.

E 2

68 A Guide to the Zoological Collections in the

The following families are illustrated in the Gallery : —

1st Family, Crangonidse, Shrimps : the single genus
Crangon is found in Indian Seas on sandy
bottoms and in deep water. Two species of
Indian Shrimps are exhibited.

2nd Family, Glyphocrangonidae : the genus Glypho-
crangon is commonly dredged in the Bay of
Bengal and Andaman Sea at depths of about
200 fathoms. In the beautiful specimens ex-
hibited notice the huge eyes which seem to be
specially developed to catch the very small
amount of sunlight that penetrates to the depth
at which theise animals live, just like the large
eyes of owls and other twilight-loving animals.

3rd Family, Alpheldse: two genera Alpheus and
Athanas occur in Indian waters. Alpheus is
exceedingly common in the reefs of the Anda-
man and Laccadive Islands, living usually in
pairs, male and female, in crannies in the rocks,
in the cavities of sponges, corals, etc.

4th Family, Psalidopodidae : one genus Psalidopushz.'s.
been dredged in the Andaman Sea at depths of
400 to 500 fathoms. To this great depth no
sunlight can penetrate, and it is not surprising
therefore to find that Psalidopus has the eyes
reduced to mere rudiments. The first pair of
thoracic legs is peculiar in ending, not in
pincers, but in two blades, which cut across
each other like scissors.

5th Family, Hippolytidse. To illustrate this family
specimens of the genus Hippolyte are shown,
being the only form that occurs in the Seas of
India.

6th Family, Pandalidae. Fine specimens of the genera
Pandalus, Dorodotes, and Heterocarpiis, all
from the depths of the Indian Seas, are exhibit-
ed. Heterocarpus is highly luminous.

Invertebrate Gallery of the Indian Museum. 6g

7th Family, Pontoniidse. This family is represented by
specimens of a Pontonia which lives in pairs,
male and female, within the shell of the large
bivalve Mollusk Tridacna.

Sth Family, Acanthephyridge. The curious Hoplopho-
rus which has the antennal scale sharply pointed
and serrated along the edge, Ephyrina, and
Acanthephyra, belong to this family. All come
from great depths.

9th Family. Palgemonidae. Fresh-water Shrimps. Ob-
serve the gigantic male specimen of Talxmon-
carcinus from Trivandrum, the second pair of
legs of which (in the male only] are more than
twice the length of the body,

loth Family, Nematocarcinidae. Ne7iiatocara'nus with
its long legs ending in brush-like tufts is found
in the great depths of the Bay of Bengal.

nth Family, Pasiphaldas. Pasiphlie, Parapasiphde

and Psathyrocaris all come from the depths of

the Sea.

Several other families of Caridea exist but are not,

as far as is known, represented in the seas or rivers of

India.

/3. DECAPODA BRACHYURA.

[€:a0£0 49.5l,64-69].

This sub-Order includes the Crabs.

The Brachyura differ from the other Decapoda in the
great development and concentration of the cephalothorax,
and in the rudimentary character of the abdomen.

The abdomen, the segments of which are small and are
usually more or less fused together, is bent up beneath the
thorax : in the male it usually carries but two pairs of very
rudimentary feet, and although in the female there are
four pairs of hairy biramous feet, these are of no use in
locomotion and are only used in the breeding season to
carry the developing eggs. The eyes are lodged in distinct

70 A Guide to the Zoological Collections in the

orbits, and there are cavities into which the short anten-
nules can be folded. The maxillipeds have lost their
foot-like appearance, and the last (third) pair have the
basal joints expanded to form complete doors in front of
the mouth.

The disarticulated specimen of the common Indian
edible crab [Scylla serrata) in Case 49 should be carefully
compared with the neighbouring disarticulated specimens
of Penasus and Nephrops.

The majority of the Crabs are marine, but there are
numerous fresh-water species, and a good many species
live entirely on land quite remote from either sea or river.
The great majority of the marine species are found with-
in the hundred-fathom line, and although about sixty spe-
cies have been dredged at greater depths, only two or three
have been taken in water over a thousand fathoms deep.

The Brachyiira are subdivided into five tribes — Cy-
clometopa, Catometopa^ Oxyrhyncha, Oxystomata, and
Anoinala, the last presenting a considerable resemblance
to some of the Anomura, e.g., to the Hippidse.

ist Tribe, Cyclometopa. Cases 65-67. — This tribe in-
eludes the common edible crabs, the swimming crabs, and
the common Indian fresh-water crabs. The carapace is
generally very much broader than long, and often forms a
wide nearly semicircular arch in front : the chelae are
usually very large and powerful. Many of the members
of this tribe reach a large size, and most of them are very
bold and active. They are arranged in numerous families,
five of which are well represented in the Gallery.

ist Family, CancridaB. — Chiefly reef-loving crabs. —
Specimens of the following Indian genera are
exhibited: Carpilius, Atergatis, Lophacta;a,
Lophozozymus, Actxa, Xantho^ ChlorodiuSy
Euxanthus, Epixanthus, Panopeiis, Chlorodop-
sisy Zozy?nus, EtisuSy Leptodius, Pseudoziiis,
Heteros/us, Pilumnus, Actumnus Menippe,
Eudora.

Invertebrate Gallery of the Indian Museum. 71

2nd Family, Trapeziidse— with the exception of Eriphiai
the Trapeziidx, are small crabs found usually
esconced in coral-stocks. The Indian genera
exhibited are Eriphia, Trapezia, Quadrella,
and Cymo,
3rd Family, Portunidae — large, fierce, marine crabs with
the last pair of thoracic legs forming broad pad-
dles for swimming. They swim sideways with
great rapidity with one of the big chelae fully ex-
tended in front. The following common Indian
marine genera are shown •.—Achelous, Scylla,
Neptunus, Thalamita, and Goniosoma.
4th Family, Podophthaiinidae. Podophthalmus vigil,
Fabr. (Case 65) with eye-stalks of enormous
length, is the only Indian representative of this
family.
5th Family, Telphusida3. — This is a very large family
as regards species, all of which however fall
into two genera — Telphusa and Paratel-
phiisa, — both of which are largely exhibited.
The Telphusidse live in fresh-water, and are very
common in rivers and ponds in India. It should
be mentioned that by several authorities the Tel-
phusidae are placed in the next tribe, of Cato-
metopa, and by all are regarded as in many
respects intermediate in structure between the
two tribes.
2nd Tribe, Catometopa, Case 69. — The members of this
tribe are characterised by having the front part of the
carapace bent downwards: some live entirely on dry land,
some frequent the muddy fiats of estuaries, and some are
marine.

The Catometopes form four families, all of which occur
in India.

ist Family, Gecarcinidse : — Land-crabs. — Specimens of
three genera, Gecarcinus, Cardisoma, and
Hylseocarcinus—ase shown in Case 69 — the last

72 A Guide to the Zoological Collections in the

two are very common in the jungles of the Anda-
man Islands.
2nd Family, OcypodJdae — Largely shore and estuarine
crabs burrowing in the sand and mud ; a few
species inhabit deep water. The Indian genera
shown are Ocypoda, Gelasivius and Macroph-
thahniis.
The Ocypoda live together in " warrens " on the sea-
shore of tropical countries, and derive their name from their
wonderful swiftness of foot. Some species possess stridu-
lating organs. Gelasinius also lives in "warrens" among
the mud flats of tidal creeks and estuaries. The males of
Gelasimus have one of their chelae not only enormously
magnified, for the purpose of fighting in the periodic con-
tests that occur for the possession of the females, but also
beautifully coloured, apparently for the purpose of attract-
ive display before the females. Observe the dried speci-
mens of Gelasimus annulipes, Edw., in Case 51 in which
this wonderful, difference between the male and the fe-
male is contrasted.

3rd Family, Grapsjdse — largely rock and reef-haunting

crabs. The genera Grapsus, Goniograpsus,

Cyclograpsus, Varuna, Sesarma, Metasesarma,

Plagusia, all from the Indian Seas, represent

this family in the Gallery. Most of the Grap-

sidae are extremely bold, active and alert.

4th Family, Pinnotherldas — Small and often soft-shelled

crabs, many of which are commensal with

Mollusks and Echinoderms. The genera Xan-

thasia and Hymenicus, both found in the Indian

Seas, illustrate this family.

3rd Tribe, Oxyrhyncha, Case 64. — This tribe, as its name

of Oxyrhynch or '"Sharp-nose" implies, is characterised

by having the carapace prolonged in front into a sharp

spine somewhat like the " rostrum " of a prawn. Very

many of the Oxyrhynchs have a globular and relatively

small carapace, together with long slender legs, and hence

Invertebrate Gallery of the Indian Museum 73

are popularly known as Spider-crabs. The Oxyrhynchs
are, for the most part, timid and inoffensive crabs trtisting
to their spiny integument for protection from their enemies,
or else bedecking their carapace with fragments of sponge
and coralline etc., for concealment.

Three families of the Oxyrhyncha are represented in
the Gallery :

ist Family, Inachidge — Tjipical Spider-crabs, several
species of which live at considerable depths.
To this family belongs the gigantic Macrocheira
kxmpferi from Japan, a specimen of which is
exhibited beside Case 64. The genera from
the Indian shallow seas are Huenia^ Doclea,
Egeria, and from the depths the huge Platy-
maia, Echinoplax, Encephaloides, Anamathiay
Pugettta, Oxypleurodon.

2nd Family, Waiidse.—The genera O^mn/^, iI//Mr^;f,
and Micippa, of which specimens are exhibited
in Case 64, are found on the reefs of the
Indian Seas.

3rd Family, Parthenopldse. — The genera Lambrus and
Parthenope are common in the Bay of Bengal
at depths of 20 to 60 fathoms. Observe the
great length of their chelipeds and the wonder-
ful sculpturing of their carapace.
4th Tribe, Oxystoma, Case 68. — In this tribe the mouth-
frame, instead of being square as it is in other crabs, is
triangular, and is often produced in front to a point,
whence the name Oxystome or " Sharp-mouth " : the incur-
rent opening into the branchial cavity instead of beiuo-
placed at the base of the great cheliped, as it is in other
crabs, is very commonly a channel placed alongside the
mouth-frame : the carapace is often globular.

The Oxystomes are, for the most part, feeble and in-
offensive crabs, living half-buried in soft mud and sand at
the bottom of the sea : some, however, are bold and active

74 A Guide to the Zoological Collections in the

swimmers. All of the four families into which the tribe
is subdivided are numerously represented in the Gallery.
1st Family, Calappidse. — In Calappa the carapace is
extended on both sides to form an arched
shield which completely roofs over the last four
pairs of thoracic legs, while the first pair of
thoracic legs, or chelipeds, are themselves ex-
panded upwards to form when flexed a front
shield for the body. In Miirsia the lateral
prolongations of the carapace form great
protective spikes. Examples of both of these
forms are shown in Case 68,
2nd Family, Matutidse. — In Matuta all the legs, except
the chelipeds, are modified to form paddles for
swimming. Matuta is one of the commonest
shallow-water crabs of the Indian Seas.
3rd Family, Leucosidse. — A large family, most of the
members of which are small and timid, and
live concealed in the mud of the sea-bottom.
Many of them have the carapace beautifully
sculptured, the sculpturings in Oreophoriis
giving the animal a deceptive resemblance to
the coral shingle in which it lives. Specimens
of the following Indian genera are shown —
Philyra, Myra^ Myrodes, Parilia, Randallin,
Leucosia, Nursia ^Lithadia, Ixa, Iphis, Oreo-
phoriis.
4th Family, Dorippidae. — The last pair or last two
pairs of legs are very small, and they spring
from the dorsal surface or back of the cephalo-
thorax and end in sickle-like claws. In these
claws is often held, as in a frame, a valve of a
mollusk shell which the crab carries as a roof or
shield. The upper surface of the shell is
usually taken possession of by a sea-anemone,
the sea-anemone furnishing an additional pro-
tection to the crab which the crab repays by

Invertebrate Gallery of the Indian Museum. 75

transporting the sea-anemone to fresh feeding
grounds. This is another instance of that per-
manent association of two animals of different
species for mutual benefit which is known as
"commensalism."
Dorippe and Ethusa (Case 68) are Indian representa-
tives of this family, the first being a common shallow-water
form, the last occurring in the great depths of the ocean.

5th Tribe, Anomola, Case 68. — The three families, Dro-
midsSt Homolidae and Ramntdx, of which this tribe
consists, were formerly placed with the Anomura. They
are here united with the Crabs in accordance with the
teaching of the late Professor Wood-Mason.

1st Family, Dromidse — represented in the collection
by Dromia and Cryptodromia. These Crusta-
ceans commonly live commensal with Sponges,
the sponge forming a cap beneath which the
crab is completely hidden : they are common on
the coral reefs of the Andaman Islands.
2nd Family, Homolidse — represented in the collection
by Paromolopsis from the depths of the Anda-
man Sea and Hypsophrys from the depths of the
Laccadive Sea. In the Homolidse the orbits
are very incomplete, and the last pair of legs
are very small and are placed on the back.
3rd Family, Raninidee — represented by Ranina, Rani-
noides, Notopus, and Lyreidus, all from the
Indian Seas. In shape these curious Crustaceans
have a resemblance to a frog. The carapace is
. long and the last pair of thoracic legs, which
are very small, are carried on the back.

y, DEOAPODA ANOMURA.

r<2ra0£0 42 mil 49].
The Anomura are in many respects intermediate
between the Macrura (Lobsters) and the Brachyura
(Crabs).

76 /4 Guide to the Zoological Collections in the

If we compare the disarticulated specimen of the
Hermit-crab, Cenohita rugosa, in Case 49 with the similar
specimens of the Prawn and the Crab between which it
is placed, we notice that the carapace, while much resem-*
bline that of both, differs from both in not includinor the
last thoracic segment, which forms a completely separate
and distinct ring. The cephalothorax again, while relatively
much larger than the abdomen, and relatively larger than
that of the Prawn, is not nearly so greatly developed as
that of the Crab ; and conversely the abdomen, though
relatively much smaller than the thorax, and not nearly
so important a part of the body, or so straightly ex-
tended as it is in the Prawn, is yet not a rudiment
tucked up out of sight, as it is in the Crab.

The cavities for the antennules and eyes, so characteristic
of the Crab, are wanting, but yet these organs are con-
siderably more concealed beneath the carapace than they
are in the Prawn. Again the third pair of maxillipeds are
not expanded at the base as they are in the Crab, and yet
are not quite claw-like as they are in the Prawn. Further-
more, the last two pairs of thoracic legs are quite peculiar
in being rudimentary.

The abdominal appendages, like those of the Crab (the
specimens in both cases being male), are incomplete and
rudimentary.

Most of the Anomura are marine, and frequent shallow
water ; some, however, inhabit the great depths of the
ocean, and a few are found in brackish estuaries, or living
entirely on land.

Of the three tribes into which the Anomura have been
subdivided, all are well represented in Indian waters and
in the Gallery.

1st Tribe, Hippidea, Case 42, — This tribe includes two
small families — the Hippidx and the Alhuneidx.

1st Family, Hippidse — represented by Hippa and
Remipes. These are small mole-like Crust-
aceans which burrow in the wet sand of the

Invertebrate Gallery of the Indian Museum. 77

seashore : the abdomen is long and narrow,

and is tucked up under the thorax, as in crabs.

2nd Family, Albuneidge — represented by Albunea,

which much resembles Hippa both in form

and in habit.

2nd Tribe, Paguridea, Case 42. — This tribe includes the

Hermit-crabs, most of which are marine; though several,

such as Birgiis and many Cenobites, are terrestrial, being

specially abundant in the dense damp jungles of the

islands of the various archipelagos of the Indo-Pacific. Of

•the four families included in this tribe, three — the Pagu-

ridas, the Cenobitidse^ and the Parapaguridse — are found in

the Indian region.

ist Family, Pagurldae — Hermit-crabs or Soldier-crabs.
The Hermit-crabs differ from all the higher
Crustaceans in having the abdomen not encased
in a calcareo-chitinous exoskeleton like the
rest of the body, but covered only with a soft
skin. For the protection of this soft vulner-
able abdomen they possess themselves of a
mollusk shell, which they change periodically
as they grow in size, and the spiral curvature
of which leads to a corresponding partial spiral
curve in the abdomen. They are common
in tidal pools, and are represented in the
Gallery by specimens of Pagurtis, Clibanarius,
and Diopencs.
2nd Family, Parapaguridse. — The Parapaguridse are
a deep-water family, differing from the Pagu-
ridde only in the structuie of the gills. They
are represented in the collection by specimens
of Parapagurus abyssorum, Pylocheles, and
Pagurodes.
Parapagurus abyssorum is invariably found living
commensal with a colony of sea-anemones
[Epizoanthus), as is well seen in the beautiful
specimen exhibited. Pagurodes also lives com-
mensal with a sea-anemone.

78 A Guide to the Zoological Collections in the

3rd Family, Cenobitidse. — These differ from the Paguridse
chiefly in having larger antennules. Several of the species
are terrestrial. The family is represented by specimens
of Cenobita and Birgus. Of Cenobita^ which much resem-
bles Pagiiriis^ several species are found swarming in the
jungles of the Andaman and Laccadive Islands. Birgus
is a gigantic land Hermit-crab which does not take
possession of a shell, and has the upper surface of the
abdomen not soft as in other Paguridea, but covered
by hard calcareo-chitinous plates. The lower unexposed
surface of the abdomen is, however, soft. In the Indian
region Birgus is known to occur only in the jungles of
the Httle island of South Sentinel in the Andaman group.
In Birgus observe that the fifth pair of legs is tucked up
beneath the carapace within the breathing chamber. Ob-
serve also that the female is furnished with a single bilobed
hairy leg on one side of three of its abdominal segments :
these legs are found in the female only, and are used for
carrying the eggs in the breeding season.

The gills in Birgus are present, but are much reduced
in size, and respiration is principally effected by the lining
membrane of the gill-chamber, which is thickened, spongy
and very vascular, and has its surface increased by being
raised into large branching excrescences. A spirit pre-
paration in Case 54 shows one side of the gill-chamber of
a small female Birgus laid open to display this modification
of its lining membrane.

3rd Tribe, Galatheida, Case 42. — This tribe includes
two families — the Porcellanida;, which have a strong
general resemblance to the Crabs ; and the Galatheida^,
which have rather a resemblance to the Lobsters. The
frontal region is prominent, and there are imperfect orbits
and imperfect fossae for the lodgment of the antennules.
The abdomen is large and symmetrical, and ends in a
large caudal fin or swimmeret. The last pair of thoracic
legs is small, and is usually carried either alongside of, or
benealh, the carai)ace.

Invertebrate Gallery of the Indian Museum. 79

1st Family, Galatheidae. The majority of the Gala-

theidsc inhabit deep water : they are represented

in the Gallery by specimens of Galathea from a

moderate depth, and of Munida, Munidopsis

and Galacantha from the great depths.

2nd Family, Porcelianidae. ^h& Porcellanidse 2iX%{owx{^

hiding under rocks and stones in tidal pools,

and are very common in India. The members

of this family have a large abdomen, but it is

bent up beneath the thorax as in the Crabs.

The Indian genera represented are Porcellana

and Petrol isthes.

In their growth, as already stated, the Macrura Deca-

poda, like the Stomapoda, usually pass through several

metamorphoses, the various stages of which differ very

greatly from the adult form. Some of these larval forms

are shown in Case 54, e.g., the Mysis stage of the Prawn,

the Zoaea and Megalopa stage of the Crab, and the

Phyllosoma stage of the Scyllaridx 2lXs.^ Palinuridse ; and

in Cases 55 and 57 are series of enlarged drawings.

Before leaving the Crustacea mention must be made
of the genus Nebalia, an example of which is exhibited
in Case 54. Nebalia is in some respects intermediate
between the Entomostracous and Malacostracous Crusta-
cea, since the abdomen has more than seven segments and
ends in a caudal fork as in Apits, and since the thoracic
limbs are bilobed plates. By Professor Ray Lankester
Nebalia is independently graded by itself, between the
Entomostraca and Malacostraca, as the sole remaining
representative of a third group named by him Leptos-
traca.

APPENDIX TO CRUSTACEA No. I.
2. ARTHROPODA PCECILOPODA.

[§Mc0txrii (!MaU-fa0i^ 56 J.
The only living representative of this group, Limulus —

8o A Guide to the Zoological Collections in the

the King-crab — has long been included among the Crusta'
ceUy but the researches of modern embryologists show
that it has much nearer affinities with the next class of the
Arthropoda, namely, with the Arachnida or Spiders,

The body of Limulus, which is enclosed in a chitinous
armour, consists of three portions — (i) a large horse-
shoe-shaped cephalothorax, (2) a hexagonal abdomen, and
(3) a long rigid post-anal spine. The cephalothorax
bears on its convex upper surface at the sides two large
compound eyes, and in front two small simple eyes ; and
in its concavity are seen six pairs of legs, the basal joints
of which are thickly beset with spiny teeth and serve as
jaws. The legs of Limulus are, in short, in what is known
as an indifferent condition, being used both in progression
and prehension, and in the mastication of food, and they
illustrate excellently the fact that the jaws and legs of
Arthropoda are "homologous organs," in other words that
Arthropod jaws are derived from legs. On the under sur-
face of the abdomen are five pairs of broad leaf-like feet,
all of which carry a series of gill-plates arranged like the
leaves of a book.

Limulus \s ionxid in India in the muddy salt waters of
estuaries.

APPENDIX TO CRUSTACEA No. II.
3. ARTHROPODA PYCNOGONIDA.

[Western SEiiU-casc 58].

Pycnogonum — the " Sea-spider ^' — has been at different
times classed with the Crustacea ^x^^ with the Arachnida :
it differs from both, and by modern zoologists is placed in
a class by itself.

pycnogonum has a long suctorial proboscis with a pair
of many-jointed palps at its base, and a very small abdo-
men with four pairs of long many-jointed legs. The male
has in addition a pair of shorter legs, which spring from
the back, and are used for carrying the eggs during the
development of the young.

Invertebrate Gallery of the Indian Museum. 8i

In Pycnogonum, as in the Spiders, the stomach is pro-
longed into the legs, almost to their end.

Most of the Pycnogonida are small, and are to be found
crawling about among the sea-weed between tide-marks,
but some of the deep-sea species are of gigantic size— the
specimen of Colossendeis ^igas from the depths of the
Andaman Sea, exhibited in Case 58, having a span of over
eighteen inches.

The stomach of this specimen is distended with mud,
so that its tubular prolongations into the legs is beautifully
displayed. This specimen is a male, and also shows well
the position and nature of the egg-carrying legs.

4. ARTHROPODA ARACHNIDA.

[QEtstern SEall-raBeg 58, 60-62].

The Arachnida include the worm-like Pentastomtda,
the Mites and Ticks, the Spiders, the Spider-like Phalan-
giida, the Scorpion-spiders, the Book-scorpions, and the
Spider-like Solifugse.

The Class thus contains a great variety of forms which,
in addition to the fact that they are all built on the
Arthropod plan of a succession of segments or somites,
have the following characters in common : — (i) that they
breathe air, commonly by tracheal sacks or "lungs," but
sometimes by true tracheal tubes, {2) that the head
and thorax are always fused together to form a single
mass, (3) that they possess two pairs of organs that can
be used as jaws, and four pairs of legs — six pairs of limbs
in all, and (4) that the abdomen has no limbs.

The disarticulated specimen of the scorpion in Case 61
shows the number and arrangement of the appendages of
the Arachnid body.

i.— ARACHNIDA ARANEIDA. (True Spiders).
[SEc0t£rn ®aU-ca0C 60].
We may very well commence the study of the Arack-
nida with the large specimens and preparations of the

82 A Guide to the Zoological Collections in the

Trap-door Spiders My gale and Scurria in Case 60, these
being types of the order A raneida or true Spiders.

In these the segments of the head and thorax are
consolidated to form a cephalothorax, which is enclosed in
a firm chitinous integument and bears six pairs of " append-
ages ", — the first pair, or "chelicerae", or jaws, ending in
fang-like poison-claws placed on either side of the mouth j
the second pair being many- jointed "palpi", or feelers,
the basal joints of which are expanded to form a second
pair of jaws ; and the remaining four pairs being long
many-jointed legs. On the dorsal (upper) surface of the
cephalothorax, towards the front and sides, are eight (in a
minority of Spiders six) large simple eyes. Behind the
cephalothorax, and attached to it by a narrow stalk, is the
large soft swollen abdomen, in which, in the adult, no signs
of segmentation can be detected. On the under surface
of the abdomen, in front, are seen the two pairs (in the
great majority of Spiders, however, there is only a single
pair) of slit-like orifices of the tracheal sacks, or "lungs".
At the end of the abdomen, round the vent, are seen the
wart-like eminences upon which the spinning-glands open,
two of these in Mygale and Scurria being of great
length.

In the Spiders the female is usually very much larger
than the male.

The rapacity and voracity of Spiders is well known :
some, such as Mygale^ lie in wait for their prey in burrows
in the earth, the mouth of the burrow being provided with
a hinged lid (Trap-door Spiders) : others, such as Lycosa^
run their prey down : others, such as SalticuSy capture
their prey by springing on it from a distance : others, such
as the common House-spider, Tegenaria, enixsi^ their prey
in funnel-like webs: the webs of others, sxxzh os Pholcus
are irregular in shape : while the webs of a large number
of Spiders, such as Epeira and Gasteracantha, have a
beautiful wheel-like symmetry.

In the family of Spiders that spring upon their prey

Invertebrate Gallery of the Indian Museum. 83

{Saltigrada;, of which Salticus and Plexippus are ex-
amples), there are certain species which resemble ants
and often live with the ants in their nests. By means of
its resemblance to the ants, and its association with them,
the spider is believed either to escape the notice of
enemies to which ants are distasteful, or to be enabled to
make unsuspected attacks upon insects that do not fear
ants. This deceptive resemblance of an animal of one
species to an animal of a quite differet species or class,
for the purpose of deceiving either enemies or prey, is
known as "mimicry ", the species that profits by the re-
semblance being known as the mimic. Specimens of an
ant-like Salticus with specimens of the ant that it mimics
are shown in Case 60, and in Case 97B of the Insect series
there are some enlarged drawings and photographs illus-
trative of this phenomenon.

The true Spiders are represented in Case 60 by speci-
mens of the following genera, almost all of which are
Indian : — My gale , Scurria, Atmetochilus, Cyriopagopus ;
Epeira,Nephila, Nephilengys, Acrosoma, Gasteracantha,
Actinacantha, Stanneoclavis, Ccerostrts, Meta, Cyclosa,
Tetragnatha ; Pholcus ; Tegenaria ; Thomisus ; Spheda-
nus, Leptoctenus, Thelictopis, Palystes, Heteropoda^ Ocy
ale, Hippasa, Lycosa ; Salticus, Plexippus, Cyllobelus^
Cytxa.

ii.- ARACHNID A PHALANGIIDA.

[SEcstern SEaU-£a0e 58].
The Phalangiida very much resemble the true Spiders,
from which they differ (i) in having the rings or somites
of the abdomen separate and distinct, (2) in having tho
abdomen joined to the cephalothorax along its whole
breadth, and not merely by a stalk, (3) in having the
mandibles or "chelicerse " in the form of small "chelae*'
or pincers, (4) in being without spinning glands, and (5)
in breathing not by tracheal sacks, but by true tracheae.

i> 2

84 ^ Guide to the Zoological Collections in the

Their legs are usually of great length. The specimens of
Phalangiumy Gagrella, and Maracandus in Case 58 re-
present this small Order.

iii.— ARACHNID A SCORPIONIDEA. (T.ue Scorpions).

[®£0Urn fflall-rasr© 61-62].
The Scorpions are characterized by their long abdomen
consisting of thirteen separate and distinct segments, the
first seven of which are short and wide and form a broad
" pre-abdomen ", while the last six are long and narrow and
form, by their union, a long narrow "post-abdomen". The
terminal segment of the post-abdomen, or "tail", contains
the poison-gland and ends in an up-curved spine, which is
perforated at its tip, like the eye of a needle, for the dis-
charge of the poisonous secretion.

The first pair of appendages, or "chelicerae", are short
pincers; the second pair, or "palpi", resemble the cheli-
peds of a lobster, and have the basal joint broadened to
form a jaw on each side of the mouth ; and the remaining
four pairs are crawling-legs, each ending in a double claw.
The eyes are found on the upper surface of the
cephalothorax — a large pair being placed in or near the
middle, and from two to five smaller eyes being found in a
line or in a patch near the front edge on either side.

The Scorpions breathe by " lungs " like those of Spiders :
of these there are four pairs, which open on the under
surface of the third to the sixth abdominal segments, as
may be seen in several of the exhibited preparations.

The Scorpions are carnivorous, feeding principally on
insects which they seize with their large pincer-like palps
and sting to death with the poison-spine at the end of the
" tail."

The females are viviparous, and several specimens, with
developing eggs and embryos, are mounted in Case 62.

The Indian genera exhibited in Case 62 are Buthus,
Pandinus, Palafnnxus, Scorpiops, Liocheles, Isometrus,
and Androctonus.

Invertebrate Gallery of the Indian Museum. 85

iv.— ARACHNIDA PEDIPALPI. (Scorpion-Spiders).

[SEestcrn ®l;ill-cti0e 62].

The Scorpion-spiders have strong resemblances both to
Scorpions and to Spiders. As in the Scorpions the seg-
ments of the abdomen are separate and distinct, but the
abdomen itself is either simple, or if there is a post-abdo-
men it is in the form of a lash-like appendage without any
poison-spine.

The jaws or "chelicerae" are like those of Spiders, and
probably contain a poison-gland ; the " palps", on the other
hand, are of the cheliped form like those of Scorpions.

The lung-sacks are two pairs, placed like those of the
Spider Mygale, as may be seen by comparing the prepara-
tions displaying the lung-sacks of both, in Cases 60 and 62
respectively. There are eight eyes, the disposition of which
is intermediate between that found in the Spiders and
Scorpions.

This small Order is represented in Case 62 by speci-
mens of Phrynussind of several species of ThelyphonuSy all
from India.

. v.— ARACHNIDA PSEUDOSCORPIONIDEA. (Book-Scorpions).
[Western SSlall-rase bS],

The Book-scorpions are small Arachnida somewhat
resembling Scorpions in shape, but having no post-abdo-
men or caudal poison-spine. They are found in old books
and beneath rotting bark, etc.

This small order is represented in Case 58 by speci-
mens of Chelifer.

vi.-ARACHNIDA SOLIFUG^.
[cEestcrn cHall-case 62].
The Solifug^f represented in Case 62 by fine speci-
mens of Galeodes, have a resemblance to the Spiders, their
palps also, like those of spiders, being leg-like ; but they

86 A Guide to the Zoological Collections in the

differ from spiders (i) in having stout pincer-like " cheli-
cerae"; (2) in having the segments of the abdomen all
separate and distinct, instead of fused together into a
single mass ; (3) in having only two eyes, instead of eight
or six ; and (4) in breathing by tracheae, instead of by
tracheal sacks or " lungs ^'.

Galeodes is common in dry sandy regions like the
Punjab and Baluchistan. Its bite is very severe.

vii.— ARACHNIDA ACARINA. (Mites and Ticks).
[mzQimx mr^ii-tnQz 58].

The Acarina form a large Order distinguished among
Arachnida by having the segments of the head, thorax, and
abdomen usually fused together into a single globular mass.

The "chelicerae" and "palps" are often modified for
piercing and sucking; and the four pairs of legs are used
for crawling, clinging, and sometimes for swimming. Very
many of them are parasites. Various species of Ixodes
and Trombidium in Case 58 represent this order.

viii.-AHACHNIDA PENTASTOMIDA.
[mtBimx ®aU-£ase 38].

The specimen of Pentastomum in Case 58 is a good ex-
ample of this small Order of parasitic and degraded Arach-
nids.

In Pentastomum the body is quite worm-like, being
made up of a succession of rings without appen dages.
Even jaws are absent, their place being filled by two pairs
of chitinous hooks placed on either side of the mouth.
Pentastomum lives as a parasite within the nasal passages
of the Dog.

5. ARTHROPODA PERIPATIDEA.

[HJtstcrtt SEaU-rasc 63].
This Class of air-breathing Arthropods contains the
single genus Peripatus, a specimen of the New Zealand
species of which is exhibited in Case 63.

Invertebrate Gallery of the Indian Museum. 87

The external form of Peripatus is much like that of a
caterpillar : the body consists of numerous segments, and
bears a pair of antennae and numerous pairs of stumpy
jointed legs (fifteen pairs in this species), each of which
ends in a pair of small claws. One of the most interesting
characters of Peripatus is that the openings of the breath-
ing-tubes, or tracheae, are scattered over the body-surface,
instead of having a definite arrangement, such as they have
in all other air-breathing Arthropods.

6. ARTHROPODA MYRIAPODA. (Centipedes and Millipedes).
[«c0tmi m^ii-c^m 63].

In the Myriapoda the body has a considerable re-
semblance to that of the appendiculate Annelids, consist-
ing of a succession of similar segments, each of which has a
pair of short appendages.

On the head are a pair of antennae, a pair of patches of
eyes, and either two or three pairs of jaws.

Breathing is performed by tracheae, or tubes which
ramify throughout the body and open at definite points
along each side: the openings of the tracheae, which are
known as " stigmata^', are indicated by pointers in the
preparations in Case 63.

The Myriapoda are divided into two Orders, the Chtlo-
poda or Centipedes, and the Chilognatha or Millipedes.

i.-MYRIAPODA CHILOPODA. (Centipedes).
[iat0tcrtt ®;aU-ra0e 63].
In the Centipedes the segments of the body are flatten-
ed, and their integument is hardened above and below to
form a dorsal plate or " tergum", and a ventral plate or
"sternum", but is soft at the sides, where, in alternate
segments, as is shown in the preparation of Scolopendra in
Case 63, the "stigmata", or openings of the tracheas, are
found. Each segment carries a pair of jointed legs which
end each in a sharp claw. The antennas are long, and the

88 A Guide to the Zoological Collections in the

second pair of legs is modified to form a pair of great poi-
son-claws, the basal joints of which are broadened out to
form additional jaws. The Centipedes are all carnivorous.
Specimens of the following Indian genera are exhibited : —
Scolopcndra^ Otostigma, Mecistocephalus^ Orphnxus,
Himantarium^ Sou tiger a.

Compare the large (aberrant) <' compound " eyes of
Scutigera with the small simple eyes of Scolopendra.

ii.-MYRIAPODA CHILOGNATHA. (Millipedes).
[®fstmi gEaU-rasc 63],

In the Millipedes the segments of the body are either
arched or completely rounded^ and, with the exception of
the first three to seven, each carries two pairs of legs.
The antennae are short and there are no poison-claws.
Tracheae open on each side of each segment of the body.
The Millipedes feed almost entirely on vegetable matter.
Specimens of the following Indian genera are exhibited : —
Glomeris, Sphseropseus, Zephronia; Acanthodesmus,Para-
desmus, Spirostreptus, Spirobolus.

Observe the two patches of simple eyes, well displayed
in the specimen of Spirostreptus aterrimus.

7. ARTHROPODA HEXAPODA- (Insects.)

[i£slv-Cra0£0 70-125].

The Insects occupy the two series of low narrow
Desk-cases that lie between the large Shell-cases travers-
ing the middle of the Gallery and the Cabinet-cases con-
taining the Protozoa and Coelenterata on either side.

The dissected preparations of the common Cockroach
(Case 70B) the common Grass-hopper (Case 75B) and the
large Wasp (Case 95A) give a good idea of the external
characters of a typical insect. The body consists of (i) a
head, made up of several (four) segments fused together to
form a single piece; (2) a thorax, formed of three seg-

Invertebrate Gallery of the Indian Museum. 89

ments known in succession as prothorax, mesothorax, and
metathorax ; and {3) an abdomen, formed of a varying
number— never more than ten— of separate segments.

The head has the following " appendages ":—(i) a pair
of jointed antennae, (2) a pair of upper jaws usually form-
ed for biting or piercing, (3) a pair of jointed lower jaws,
often formed for chewing or piercing, known as maxillae,
and (4) a second pair of maxillae, which are usually fused
together to form a low^er lip or " labium". One or both
pairs of maxillae usually carry " palps" (maxillary palps, and
labial palps). Besides these true "appendages" there
also occur on the head a pair of large compound eyes,
and often also several small simple eyes or "ocelli",
and an unpaired "labrum," or upper lip, in front of the
mouth-opening. The dissection of the Cockroach (Case
70B), displays the structural details of the typical biting
and chewing mouth.

In the Lepidopteya (Butterflies and Moths) the mouth-
parts are profoundly modified for sucking, the first pair of
maxillae being grooved and much elongated and closely
apposed to form a long suctorial tube, or " proboscis", and
the palps of the second pair of maxillae (labial palps) being
thickened and enlarged to form stout hairy cushions, be-
tween which the proboscis is coiled up when not in use,
while all the other mouth-parts are rudimentary — fsec the
enlarged drawing in Case 97C). In the Hymenoptera
(Bees, Wasps, Ants) the mouth-parts are adapted for both
biting and sucking or licking — (see the enlarged draw-
ing in Ca=e 97C).

In the Uiptera (Flies) and Hemiptera (Bugs) the
mouth-psrts are modified for piercing and sucking, the
mandibles and both pairs of maxillae, and even sometimes
the upper lip, being greatly elongated for these purposes.

Enlarged drawings of all the principal modifications of
the mouth-parts of Insects are shown in Case 9;C, the ho-
mologous parts being coloured alike throughout the series.

The thorax in a typical adult insect bears the following

go . A Guide to the Zoological Collections in the

appendages: — (i) on the prothorax a pair of jointed legs,
(2) on the mesothorax a second pair of legs and a pair of
wings, and (3) on the metathorax a third pair of legs and
a second pair of wings. The modifications undergone by
the legs for running, leaping, burrowing, clinging, swim-
ming, for seizing prey, for protection by resemblance to
other natural objects, are too numerous to be mentioned
here : they should be studied in the exhibits of the typical
groups, along with the modifications, degenerations, and
• suppressions, that occur In the wings. The structural
details of the Insect leg should be studied in the dissected
preparation of the Grasshopper in Case 75B.

The abdominal segments In the typical adult nsect are
all destitute of appendages, but In some larvae [e.g.y cater-
pillars) stumpy legs (" prolegs") are found.

The last one or two abdominal appendages are pro-
longed in the males (and females) of some msects as rods
or pincers, and In the females alone of some Insects as
stings and ovipositors.

In most Insects, as in many Crustacea, the main devel-
opmental changes. Instead of being completed within the
tgg, are continued long after the embryo has been hatched
and has become an Independent individual. In these In-
sects the adult form Is reached only after a series of moults
or " metamorphoses". The typical as well as the most
familiar series of Insect metamorphoses ("complete meta-
morphosis ") occurs in the Butterflies and Moths, In which
the embryo leaves the egg as a worm-like " larva^\ or
caterpillar. After feeding voraciously for some time the
larva encysts Itself, either In a simple chitlnous envelope
or In a silky "cocoon", and remains for a time quiescent as
a ^^ pupa'\ or "chrysalis ". In the quiescent pupa stage
the post-embryonic development Is completed, the perfect
winged insect at length emerging as an " imago ".

The number of species of Insects Is so vast that to ade-
quately Illustrate the group within the limits assigned to
it in this Gallery would be an Impossibility. The objects
therefore of the small collections here displayed are to

Invertebrate Gallery of the Indian Museum. 91

compare some of the more obvious external structural
characters of Insects, and to illustrate the natural classifi-
cation of this Class of Arthropoda, as well as to exhibit
some stages in the life-history of certain insects that affect
agricultural industries.

i. HEXAPODA THYSANURA.
[(Ease 70^].
The familiar '^ fish insect", which eats books and clothes,
illustrates this small Order. The Thysanura are wingless
insects with hairy or scaly integument and rudimentary
mouth-parts. They have a general external resemblance
to centipedes. They do not pass through a metamorphosis.
By some zoologists they are regarded as aberrant Orthop-
tera.

• ii. HEXAPODA ORTHOPTERA.
[OCases ZOf-ZSOT].

Insects with typical biting and masticating jaws, and
with two pairs of wings, the front pair of which are often
parchment-like. In the females of some species, however,
the wings are absent or rudimentary, as may be seen in
some of the exhibits of Mantidas. The abdomen usually
ends in rods or stylets, which in the female (as in the
locusts) may be used as ovipositors.

In many Orthoptera {e.g., the Crickets, Locusts, and
Grasshoppers) the males produce powerful musical sounds
by the rhythmical scraping together of file-like plates
which are developed either at the bases of the hard fore-
wings or on the inside of the "thighs" of the last pair of
legs : in the first case the wings of opposite sides are
scraped across one another, one wing serving as a bow
and the other as a fiddle ; and in the second case the thigh
is used as a bow, being scraped against the fore-wing which
acts as a fiddle. It is only very exceptionally that these
sound-producing or stridulating organs are possessed by
the female also.

92 A Guide to the Zoological Collections in the

The young of typical Orthoptera differ from the adults
chiefly in the absence of wings, and the metamorphoses
consist of a series of moults in which the wings are gradu-
ally acquired.

The Orthoptera form a large Order of which the follow-
ing family-types are represented in the Gallery: —

ist. Forficulidae, or Earwigs, (Case 70B);

2nd. Blattidge, or Cockroaches, (Cases 70B and 70C);

3rd. Mantidas or Praying- insects, (Cases 71A-74C);

4th. Phasmidse, or Stick-insects and Leaf-insects, (Case
75A), the wingless forms resembling sticks,
the winged forms resembling leaves ;

5th. the Acridiidae, or Grasshoppers, (Cases 75B-77A);

6th. the Locustidae, (Cases 77B.77C);

7th. the Achetidae, or Crickets, (Case 77C).

In the above seven families, which constitute the sub-
Order Orthoptera genuina, the fore-wings are hard and
parchment-like.

Family 8th, the Termitidae, or Termites, popularly known
as "White Ants ", although they are not ants
at all. The Termite communities consist of
sexually-perfect males and females, both of
which are winged, and of sexually-aborted males
and females, or "neuters ", which are wingless.
The neuters are of two kinds, namely (i)
"soldiers '', with large mandibles for fighting,
and (2) ordinary " workers " with smaller
mandibles. Besides males and females, sol-
diers and workers, the Termite communities
also contain wingless larvae and pupas. The
females, or "Queens", when distended with
eggs are of enormous size. In Case 78B spe-
cimens of Queens, Soldiers, Workers, and pupae
are shown ; and in Case 78A is a series of
enlarged drawings illustrating ail the forms of
Termes lucifugus.

Invertebrate Gallery of the Indian Museum. 93

Family gth, the gnat -like May-flies (Ephemeridge) the

larvae of which are aquatic. Specimens of

May-flies, along with an enlarged drawing of

an aquatic larva, are shown in Case 78B.

The loth Family represented is that of the Libelluiidae

or Dragon -flies (Case 78C) the larvae of which also are

aquatic. These three families, — Termites, May-flies, and

Dragon-flies have both pairs of wings, when present,

thin and membranous like those of the Neuroptera^ and

are hence known as Pseudoneuroptera.

iii. HEXAPODA NEUROPTERA.
[OTasc 79.^].
Insects usually with biting mouth-parts and with thin
membranous wings. Metamorphosis "complete^'. The
Ant-lions in Case ygA represent this Order. The larval
ant-lion, a specimen of which, along with a much-enlarged
drawing, is shown, digs little funnel-like pits in the sand, at
the bottom of which, in concealment, it lies in wait for prey.

iv. HEXAPODA STREPSIPTERA.

This small Order of degraded parasitic insects is re-
presented by specimens and enlarged drawings of Stylops
in Case 88B showing the larva ; the male, with contorted
rudimentary forewingsand well developed hindwings; and
the maggot-like wingless and legless female. The larvae
and the maggot-like females live as parasites within he
abdominal cavity of wasps and humble-bees. It should be
mentioned that by some modern entomologists the Strep-
siptera are regarded as an aberrant family of Coleoptera
(Beetles) approaching the Cantharidx.

V. HEXAPODA HEMIPTERA. (Rhynchota).
[(Eits^s 79f-80(!l].
Insects with the mouth-parts usually modified for pierc-
ing the integument of animals and plants and sucking

94 A Guide to the Zoological Collections in the

the underlying juices. An enlarged drawing of the mouth-
parts is shown in the series in Case 97C.

This large Order includes (i) the wingless Lice, the
Plant-lice, and the Lac and Cochineal Insects, which to-
gether constitute the sub-Order Hemiptera Aptera ; {2)
the Cicadas, in which both pairs of wings are well developed
and are usually membranous throughout, constituting the
sub-Order Hemiptera Homoptera ; and (3) the Bugs of all
kinds, which have the bases of the fore-wings hard and horny,
and form the sub-Order of Hemiptera Heteroptera.

vi. HEXAPODA DIPTERA.

This large Order includes the common Flies, the Flesh-
flies, the Gad-flies, the Gnats, Mosquitoes, and Crane-flies,
and the wingless Fleas. In all, the mouth-parts are modified
for piercing and sucking, as is shown in the enlarged draw-
ing in Case 97C, and only one pair of wings — the fore-
wings — is developed, the hindwings being reduced to small
knobs known as "halteres". In the Fleas both pairs of
wings are microscopic rudiments.

vii. HEXAPODA LEPIDOPTERA.

[(Ea0£0 98^ t0 125(E].

This very large Order includes the Butterflies and
Moths, in which the mouth-parts are peculiarly modified to
form a sucking-tube or " proboscis " as already described
(see also Case 97C). Both pairs of wings are well devel-
oped, except in the females of a few species of moths, in
which the wings are quite rudimentary, and are partially or
completely covered with the microscopic scales and hairs
that form the beautifully variegated coloration of the but-
terfly's wing. The metamorphoses of these insects are
too familiar to need further mention.

The Lepidoptera are divided into two sub-Orders, name-
ly (i)the Rhopalocera, or Butterflies, (Cases 98A to 115A)

Invertebrate Gallery of the Indian Museum. 95

in which the antennae are clubbed at the tip, and are
always carried either erect or extended; and (2) the
Heterocera, or Moths (Cases 115B to 125C) in which the
antennae vary considerably in form, but are not clubbed
at the tip, and are never held erect or extended in repose,
but are then almost invariably folded away beneath the
wings. A good collection illustrative of both sub-Orders
is exhibited in Cases 98 A to 125C. For the Indian Rho-
palocera, or Butterflies, the student should consult Mr. de
NiceviWc's '* Butter/lies 0/ India, Burma, and Ceylon",
published by the Calcutta Central Press Company.

viii. HEXAPODA COLEOPTERA.
[€nsz& 82^-93 U].

This very large Order comprises the Beetles, which are
characterised by having mouth-parts of the typical biting
and chewing type ; by having the forewings hardened to
form horny " elytra ", or cases for the protection in repose
of the membranous hindwings, which alone are used in
flight ; and by passing through a complete metamorphosis.
In some cases the elytra alone are present ; or the elytra
may be soldered together : and in a few forms, e.£., the
females of some species of glow-worms, the wings are
altogether wanting.

ix. HEXAPODA HYMENOPTERA.
[OTase© 93(11-9 7f].
Insects with the mandibles adapted, like those of
Orthoptera, Neuroptera, and Coleoptera, for biting, but
with the 1st maxillae and 2nd maxillae (labium, or lower
lip) elongated and peculiarly modified for licking and
sucking (Bees). Wings are sometimes absent, but are
usually present, and then the forewings interlock with the
hindwings on each side by means of booklets on the outer
edge of the latter. The abdomen is much narrowed at
its junction with the thorax to form a stalk, and in the

96 A Guide to the Zoological Collections in the

female the abdomen ends in an ovipositor, which has
sometimes a poison-gland connected, to form a poison-
spine or "sting '\ The metamorphosis is complete.

The Order, which includes the Saw-flies, Gall-wasps,
Ichneumon-flies, Ants, Solitary wasps, Social wasps, Soli-
tary Bees, and Social Bees, is illustrated in Cases 930 —
97B. The marvellously complex economy of the social
Hymenopfera, especially of the Ants, can only be men-
tioned here. The communities consist (i) of winged males
which are usually short-lived, (2) of winged females, which
are usually very few in number, and (3) of a vast number
of usually sexually-undeveloped females which may be
either winged (Bees) or wingless (Ants), and are known
as "workers". Among the ant communities the "work-
ers " are sometimes of two kinds — *' soldiers " with large
mandibles, and "true workers".

Practically, owing to the transient existence of the
males and the paucity of the sexually-perfect females, a
community usually consists of a "Queen" and a horde of
"workers", with larvae and pupae.

PHYLUM V OF THE COELOMATA.

ECHINODERMATA.

[Sasteru fflalUas^s 17—36].

The members of this phylum are characterised by the
radial symmetry of the body. It is only in some of the
atypical Holothuroidea that bilateral symmetry occurs.

The Echinodermata form a very definitely circumscribed
group, and their relations to the other great groups are
by no means agreed upon.

The Echinodermata are marine animals usually of a
quinque-radial or five-rayed star-shape and covered with a
skin which is always thick and stout and is often so
impregnated with lime-salts as to form a rigid stony case.
For further protection the hard stony integument is often

Invertebrate Gallery of the Indian Museum. 97

thickly covered with stout calcareous spines, and some
of these are often modified to form beak-like or pincer-like
organs known as " pedicellariae," examples of which are
shown in Wall-case 18.

The Echinodermata are specially characterized by the
possession of a "water-vascular system/' by which a
watery fluid is distributed through the body, assisting
respiration and the excretion of waste products and aid-
ing in locomotion. This system is also in communication
with the external sea-water.

The details of the water-vascular system, which are
shown diagrammatically in the enlarged drawing in Case 18
and are also displayed in several dissections, are typically
as follows : —

Through a sieve-like usually external plate, known as
the " madreporic plate," the sea-water percolates and
passes along a canal, known as the *' stone-canal," into a
circular canal which surrounds the gullet. On this "circular
canal " there are usually found several reservoirs known as
" Polian vesicles, " and from the circular canal five radial or
"ambulacral" canals branch off, one into each ray of the
body. From both sides of the ambulacral canals erectile
tubes are given off, and these, which are known as " am-
bulacral feet " or "tube feet," pass through pores in the
bcdy-wall and project outside the body. The tube-feet
commonly end in a sucker, and it is by the contraction of
the turgid tube-feet, when the suckers are firmly adherent
to some external object, that the typical Echinoderm
travels. Sometimes the water- vascular system is prolong-
ed into branching tentacles which surround the mouth,
as is seen in the Holothurian, Thyone, exhibited in
Case 35.

The alimentary canal differs much in the different
groups of the Echinodermata : its details in several of
the groups are shown by dissections with explanatory
notes. In some groups the mouth is armed with powerful
teeth, specimens of which are exhibited (Cases 28-29).

pS A Guide to the Zoological Collections in the

Special breathing organs are not generally found in the
Echinodermata. The water-vascular system aids in res-
piration, as does also the general surface of the body-cavity
and its contained organs, and often also the general external
surface of the body.

The Echitiodermata possess blood-vessels, in which
colourless blood circulates ; they are hard to trace, but
can be seen in the dissection of Holothuria in Case 36.
They also possess a nervous system, and in the Star-fishes
there are simple eyes, which are placed at the tips of the
rays, but are hard to trace.

The Echinodermata do not usually produce offspring
by budding, but when an animal such as a Star-fish loses
one of its rays, not only can a new ray be grown from the
stump, but it appears that the detached ray also can often
by growth and budding give rise to a new Star-fish. (See
specimens in Case 18).

In some Star-fishes the rays are thrown off whenever
the animal is disturbed, so that this regeneration of new
rays must be a very common event. The ordinary repro-
duction of new individuals, however, is always sexual — the
sexes being with few exceptions separate.

The Echinodermata are divided into five great Classes
— (i) the Asteroidea or Star-fishes, (2) the Ophiuroidea
or Brittle Star-fishes, (3) the Crinoidea or Sea-lilies, (4) the
Echinoidea or Sea-urchins, and (5) the Holothuroidea or
Sea-cucumbers.

I. ECHINODERMATA ASTEROIDEA (STAR -FISHES).

[Casttrit Ktitll-ras£0 17-24.]
The Star-fishes are characterized by their pentagonal
or five-rayed shape. Some, however, have more than five
rays [e.g,^ the Acanthaster exhibited in Case 24 has twenty-
one, and the Brisinga in Case 23 has thirteen). On ex-
amining a typical Star-fish we find it to consist of a
central flat disk with five regular flat-pointed rays, the
whole being encased in a thick leathery integument hardened

Invertebrate Gallery of the Indian Museum. 99

by spiny or granular plates of lime. On the under sur-
face of the disk we find, in the centre, a large mouth, and
radiating from the mouth five channels or furrows — the
ambulacral furrows — from which the ambulacral tube- feet
by means of which the Star-fish progresses, emerge in rows.
On the upper surface of the disk we find, in the centre,
usually but not always, the anus, and near the margin
of the disk and between two of the rays, the madreporic
plate. In some forms there is more than one madreporic
plate— ^.^., the Acanthaster, in Case 24, has eight. In some
forms — e.g., Astropecfen — there is no anus. The more
apparent details of the internal structure of the Star-fishes
(such as the arrangement of the water-vascular system, the
stomach with its pouches extending into the rays, the genital
glands, etc.) are shown in several dissections to which
explanatory notices are attached.

The Star-fishe sare all marine, and live at all depths,
from the tide-marks down to depths of nearly three
thousand fathoms. The shallow-water species prefer hard
ground, such as rocks and reefs and beds of hard sand,
where they find in abundance the Mollusca and the small
Crustacea upon which they feed. The deep-water or
abyssal species dwell upon the ooze of the ocean-bottom,
and some of these species appear to gorge themselves
with the ooze for the sake of the minute particles of
living or dead animal-matter that it contains. Many
species of Star-fishes are gregarious — that is to say they
live together in large swarms ; and some species have been
observed to pair at the breeding season. In one family
of Star-fishes, of which the magnificent specimen of Hymen-
asternobilis in Case 23 is an example, the eggs are carried
about in a nest-like pouch on the back of the animal until
the young are hatched.

The Asteroidea are represented by species of the
following genera, all from the Indian Seas :^

(i) From the littoral, and from shallow-water :—'
Ar chaster; Craspidaster^ Astropecten, Luidia, Stellaster,

100 A Guide to the Zoological Collections in the

Goniodiscus; Pentaceros, Culcita^ As'terodiscus ; Anthenea;
Asterina ; Linckiay Ophidiaster, Nardoa^ ChxtasteVy
Fromia ; Echinaster, Acanthaster ; Asterias.

(2) From the deep-sea : — Pararchaster, Pontaster^
Dy taster y Persephonaster^Pseudarchaster ; Porcellanaster,
Styracaster, Hyphalaster; Dipsacaster; Petitagonaster,
Calliaster, Milteliphaster, Nymphaster^ Paragonaster^
Mediaster, Anthenoides ; Palmipes ; Zoroaster ; Hymen-
aster, Marsipaster ; Pedicellaster ; Brisinga, Freyella.

2. ECHINODERMATA OPHIUROIDEA. (BRITTLE
STAR-FISHES).

[©astern Mnll-cnQts 24-26.]

The Ophiuroidea resemble the Asteroidea in external
form ; but the arms, which very rarely exceed five in
number, are relatively much longer and more attenu-
ated, and are much more clearly and sharply marked off
from the disk ; and the disk is more circular and relatively
of much smaller size. In the Asteroidea, again, as is seen
in the dissections in Cases ig and 21, the stomachal caeca
pass into the arms, as do also the generative organs ; but in
the Ophiuroidea^ as is seen in the dissections in Case 25,
the viscera are entirely confined to the disk and do not
extend into the arms. In the Ophiuroidea also an anus is
always wanting.

On examining a typical Ophiurold, such as the large
specimens of Ophiothrix galatese in Case 26, we see that
the animal consists of a small round disk, in which the
viscera are lodged, and of five long thin snaky arms orrays.

The disk, on the upper surface, is seen to be covered
with small scales the surface of which is beset with little
spinelets, while the arms are enclosed in much larger
scales or plates, of which those at the sides bear long
flat spines in several series. Five pairs of plates at the
margin of the disk, near the bases of the arms, are much
enlarged : these are known as the " radial shields."

On the under surface of the disk we see, in the centre,
the mouth bounded by five pairs of mouth-plates (one of

Invertebrate Gallery of the Indian Museum. loi

which is the madreporic plate) with their adjacent mouth-
shields, each mouth-plate bearing a series of teeth and
tooth-papillae ; and radiating from the mouth-shields, the five
" arms, " or rays, with their large transverse under-plates.
The rays, however, have no open ambulacra] groove as
they have in the Star-fishes, but the ambulacral groove is
completely closed in by a series of ventral or "super-
ambulacral" plates, between which and the side-plates the
tube-feet emerge.

The under surface of the disk, beyond the mouth-shields,
is thickly beset with little spinelets, and on this surface,
on either side of the base of each arm, is seen a broad
fissure known as the genital cleft, through which the
reproductive glands discharge their contents.

The Ophiuroidea live at all depths, from between tide-
marks down to the abysses of the ocean. They appear
to flourish best in the seas of the tropics, as is illustrated
in the Andaman Sea, where the trawl is never worked at
depths of 100 to 250 fathoms without bringing up scores
of specimens [Ophiacantha, Ophiocamax^ Ophioglypha),
and where at low-water the pools of the coral reefs are
often full of writhing masses of brittle-stars [Ophtothrix^
Ophiocoma, Ophiomaslix),

The Ophiuroidea consist of two families — the Ophiuridse
or typical forms, in which the rays are simple and un-
branched ; and the Astrophytidx^ in which the arms are
usually branched.

jst. The OphiuridsS are represented in the exhibited
collection by specimens of the following genera, all from
the Indian Seas : —

From the reefs -.—Pectinura, Ophiolepis, Ophiozona,
Ophiocnida, Ophiophragniics, Ophiocoma, Ophiarthrum^
Ophiomastix, Ophiothrix, Ophiocnemis.

From the great depths : — Ophiernus, Ophioglypha^
Ophiomusium, Ophioca max»

2nd. The Astrophytidae are represented by several forms
from the depths, none of which, however, appear to corre-

102 A Guide to the Zoological Collections in the

spond with any hitherto described species or genera, with
the exception of an Astroschema {Astroschema Jlosculus)
from 88 fathoms in the Bay of Bengal,

3. ECHINODERMATA CRINOIDEA (SEA-LILIES, FEATHER-
STARS).

[eastern m^XU^QZ 27].

The Crinoidea somewhat resemble the Ophiuroidea,
especially the Astrophytidse, in external form, consisting
of a central disk, in which the viscera are lodged, and of
slender arms radiating from the disk, which lodge the
ambulacral canals : but the disk of the Crinoids, instead
of being flat and depressed, is either conical or cup-
shaped, and is often attached by a long stalk ; and the
arms are divided from their base into numerous feather-
like branches.

There are two families of Crinoidea— the Pentacri-
nidse or stalked Crinoids, and the Comatulidae or free-
swimming Crinoids, which are stalked only in the young
state.

ist. The principal external characters of the Pentacrl-
nidSB may be learned from an examination of the speci-
men of Metacrinus in Case 27. In Metacrinus we find a
long stalk by which the animal is fixed, back downwards :
it consists of a series of pentagonal stony (calcareous)
segments joined together one above another : at regular
intervals along the stalk are seen whorls of similarly
segmented branchlets known as "cirri". At the end of
the stalk comes the disk, which consists of a small stony
(calcareous) cup placed mouth upwards. From the edge
of the disk spring five arms, which are built up of stony
segments, and each of which divides and subdivides
several times into long branches fringed on both sides
with feathery processes known as " pinnules ". The
concave inner surface of the cupped disk is covered
by a thick leathery skin, and in the centre of it can be

Invertebrate Gallery of the Indian Museum, 103

seen the orifice of the mouth : the inner concave surface
of the arms and of their branches is also covered with the
same thick skin, through which the ambulacra! feet emerge.
As in the Ophiuroidea, the viscera are confined to the
disk, and the ambulacral water-vascular system extends
along the arms and pinnules.

2Kd. The chief characters of the Comatuiidae may be
learned from an examination of the fine specimens of
Actinometra in Case 27. In Actinometra the animal is
only fixed in its larval stages : in its adult stages it is free.
Here we find a conical disk, with a flat oval surface, from
which five long much-branched feathery arms radiate.
The under surface of the disk — whicfc is really the upper
or dorsal surface, for the animal moves about on its back,
face upwards — is covered with a pyramid of stout calcare-
ous plates, from which one or two whorls of stout segment-
ed "cirri" radiate. The cirri are prehensile, and by
means of them the animal anchors itself to foreign objects.
The upper surface of the disk — which is really the
under or ventral surface — is covered with a leathery skin
channelled by the wide ambulacral grooves as they pass
to the arms, and presents to view, near the margin, the
depressed oval mouth, and near the centre the long tubu-
lar anus. The arms are merely a repetition of those
of Metacrinus. In neither Metacrimis nor Actinometra
do we find a madreporic plate, this structure being absent
in the Crinoidea, in which Class the ambulacral system is
filled from the general body cavity or ccelom.

The greater number of the Crinoidea are extinct, and
their fossil remains form vast beds of limestone rock, in
the Palaeozoic formations (Cambrian, Silurian, Devonian,
and Carboniferous) known as Crinoidal Limestone.

The existing Crinoidea usually occur at some depth.
In the Indian area the Comatuiidae zre commonly dredged
on rocky bottoms at from 15 to 60 fathoms, and the Penta-
trinidx occur in the Andaman and Laccadive Seas at
and near 500 fathoms.

This Class of the Echinodermata is represented in the

IT)4 A Guide to the Zoological Collections m thi

collection by fine specimens of Pentacrinus, Metacrinus^
Actinometra and Antedon, — all from thelndian Seas.

The extinct species are represented by fossil speci-
mens of Pentacrinus from the Permian, and of Penta-
tremites from the Carboniferous.

4. ECHINODERMATA ECHINOIDEA (SEA-URCHINS, SEA

EGGS).

[Eastern giEaU-£a0C0 28-34].

In the Echinoidea the body is spherical, or heart-
shaped, or disk-shaped, and is always enclosed in a shell
or test formed of calcareous plates which in all living
forms, except Phormosoma and Asthenosoma, are immov-
ably sutured together. These calcareous plates are always
more or less densely covered with movable spines — there
usually being a close covering of small spinelets, with very
much larger spikes interspersed. Three-pronged pedicel-
lariae are very commonly found among the spinelets, these
in Cidaris, for example, being large enough to be easily
distinguished by the naked eye.

The external characters of a typical Regular Echinoid
are well shown in the specimen of heterocentrotus trigon'
arius (Case 28), which has been dried, denuded of all its
spines, and coloured.

Here, looking from above, we find the plates of which
the test is composed to fall into twenty meridional rows
arranged in ten pairs. Five of these paired rows of
plates are narrow, and are closely perforated with numer-
ous pairs of pores. These pores are for the passage of
the ambulacral tube-feet. The perforated plates are there-
fore known as ambulacral plates, and the five rows of
them are collectively known as the " radii ". They are
coloured crimson in the specimens.

Alternating with the radii are five also double rows of
very much broader plates which are not perforated : these
are known collectively as the " interradii ", and are coloured
blue in the specimens.

Invertebrate Gallery of the Indian Museum. I05

The poriferous radii and the imperforate interradii do
not meet at the apex of the test, but the apex of the test
is occupied by a star-shaped area formed by ten plates
surrounding a central orifice. This central (apical) orifice
is the " periproctal area ", and in life it is covered in with
small scaly plates, and is perforated by the anus. Of the
ten plates which surround the periproctal area, five are seen
to occupy the summits of the radii, while five much larger
ones occupy the summits of the interradii : those which
surmount the radii are known as " radial plates" (formerly
termed ** ocular plates"), while those which surmount the
interradii are known as "basal plates" (formerly termed
"genital plates "). Each basal plate is conspicuously per-
forated by a large pore fo r the duct of the underlying geni-
tal gland, and one of the basal plates is much enlarged and
spongy. This large spongy basal plate is the madreporic
plate, through which the sea-water filters into the stone-
canal, and so to the water-vascular system.

Looking from below we see that neither the radii nor
interradii quite meet at the lower pole of the shell, but
we find there a large orifice. This is known as the peris-
tomial area, and in life it is filled up with a scale armour
df little plates, except in the centre where the mouth lies.

The intact peristomial area, with the mouth and the five
large teeth characteristic of the Regular Echinoids, are
seen in the neighbouring specimen of Dorocidaris (Case
28).

The arrangement of the mouth and of the five jaws, with
their " pyramids ", which work on the " braces " and *' com-
passes" and enclose the sharp-pointed teeth, is shown in
the neighbouring dry preparation of the mouth-parts of
Salmacis (Case 28).

Alongside of the jaws of Sahnacis is shown half of the
test of the individual from which the jaws were removed :
this preparation is meant to exhibit the internal upstand-
ing processes (or *' auricles") of the ambulacral plates, which
support the " pyramids " and give attachment to the

io6 A Guide to the Zoological Collections in the

muscles which move the jaws. Next to this preparation is
dried and denuded test of Cidaris^ also opened to display
the "auricles", which however in Cidaris are upstanding
processes of the interradial plates. The ^- auricles " which,
like the "pyramids", jaws, and teeth, are five in number,
are known collectively as the " perignathic girdle ".

The division of the shell into radii and interradii corre-
sponds with certain constant arrangements of the internal
organs : a radial water-vessel, accompanied by a nerve and
a blood-vessel, traverses each radius, while a generative
gland lies in each interradius.

The details of the digestive, water-vascular, and repro-
ductive systems are shown in the spirit preparations of
Salmacis (Case 29), which also display well the mouth-parts
in situ, and the muscles by which they are moved.

The above remarks apply only to the Regular Sea-
urchins— the Cidaroida and Diadernatoida — that have
spheroidal tests, at the poles of which the alimentary canal
opens.

There are, however, two large groups of Irregular Sea-
urchins, in which the test is no longer spherical or even cir-
cular, and in which the mouth and anus are often excentric.

The first of these groups is the Clypeastroida, of which
we may take Echinodiscus Ixvis as a type.

In Echinodiscus Isevis (Cases 32-33) we find the body
to have the form of a flat shield-shaped cake or irregular
disk. On the flat under (ventral) surface we find, in a
central position, the mouth, and nearly midway between
the mouth and the edge of the disk the anus. Radiating
from the mouth are the ambulacral grooves, which bifurcate
and branch again and again, and have pores so minute as
to be visible only with a pocket-lens.

On the upper (dorsal) surface we notice, in the centre,
the basal (genital) plates all fused together to form a single
large pentagonal madreporite, in only four of the angles of
which are genital pores found. Radiating from the apical
madreporite is a regular five-rayed " rosette", each petal
of which is formed by series of ambulacral pores.

Invertebrate Gallery of the Indian Museum. 107

The principal internal characters of the Clypeastroida
are exposed in the spirit-dissection of Echinodiscus Ixvis
(Case 33), where the mouth is seen to be armed with teeth
which, however, are more horizontal than vertical ; the
" pyramids " are broad and flat, and are united together to
form a large pentagonal plate, and there are no braces
and compasses. The nature of the mouth-parts, as of the
" perignathic girdle " and of other parts of the interior of
the test, is shown in several dry preparations in Case 32.

In the Spatangoida the test is very commonly heart-
shaped. Looking at such a form as Lovenia^ Cases 33-34,
on the under (ventral) surface, at the broader end of the
" heart," we find the toothless valvular opening of the
mouth, while at the apex of the "heart'' the periproct is
seen. On the upper (dorsal) surface, near the centre, we
notice the five small basal (genital) plates, three or four of
which are perforated, while the fifth, which is imperforate,
forms a small " madreporite ". Radiating from the genital
plates is an irregular ambulacral " rosette "of five rays, four
of which are conspicuous by their breadth and by the size
of their pores, while the fifth by reason of the minuteness of
its pores is at first sight likely to be overlooked. Owing
to the absence of teeth no "jaws" and no "perignathic
girdle " are found among the Spatangoida.

The Echinoidea are found in all seas, and at all depths
from tide-marks to the abysses of the ocean. In the Indian
region the Regular Echinoids are met with in profusion on
the coral reefs — Cidaris dind. Phor?nosoma, however, being
most abundant at depths of 150 to 500 fathoms: the Clype-
astroida are very common in shallow muddy water, as for
instance along the estuarine coasts of the great rivers of the
Bay of Bengal : while the Spatangoida have been obtained
in greatest number on muddy bottoms in 400 to 600
fathoms.

Such being their range, their habits of life are various :
the shallow- water forms live on Molluscs and Crustacea, on
sea-weed and even on decaying vegetable matter ; the deep-

108 A Guide to the Zoological Collections in the

water and toothless forms appear to extract nourishment
from the organic matter, animalcules, etc., found in sea-mud.

The Echinoidea are represented in the exhibited col-
lection by the following genera — all from the Indian Seas :
— Cidaris, Dorocidaris, Porocidaris, Phyllacanthus,
Goniocidaris ; Phormosoma, Asthenosoma ; Diadema^
Echinothrix, Astropyga ; Temnopleurus^ Salmacis, Mes-
pilia ; Heterocentrotus, Colobocentrotus, Echinometra,
StomopneusteSy Echinostrephus ; Toxopneustes, Trip"
neustes, Prionechinus, Fibulariay Clypeaster, Laganum^
Peronella, Echinodiscus, Arachnoides j Echinolampas ;
Brissus^ Metalia, Brissopsis, Maretia, Lovenia, Homo^
lampas.

Besides the above, a small collection of Australian forms
is exhibited, and a good collection of fossil types. The
fossil specimens are distinguished by a red wafer.

ECHINODERMA HOLOTHUROIDEA (SEA-CUCUMBERS).

[©astn-n SeaU-fa0£0 35-36]-

The Holothuroidea are long worm-like or cucumber-
shaped Echinoderms with a thick leathery skin which is
usually soft and strengthened, though but slightly, with
scattered microscopic spicules and perforated platelets of
various form composed of carbonate of lime. In one small
group of deep-sea Holothuroidea, however, represented in
the collection by the beautiful specimens of Deima, the in-
tegument consists of a continuous mosaic of large calcareous
plates which form a rigid test not unlike that of a Sea-
urchin. In the Holothurians the water-vascular system
undergoes a remarkable modification ; it becomes more
respiratory and less locomotor in function, the ambu-
lacra being reduced in number to three or to two, or even
disappearing altogether {Synapta, Caudina), while round
the mouth the system becomes extended into a crown of
large and often much-branched oral tentacles : these are
displayed, fully extended, in the specimen of Thyone in
Case 35.

Invertebrate Gallery of the Indian Museum. 109

In cases where the ambulacra are reduced to three^
these are commonly placed close together on one face of
the body, which then becomes a flattened ventral surface or
"foot'", upon which the animal progresses like a snail or
slug, while the opposite surface becomes a strongly convex
back. This is excellently shown in the specimens of Mul-
leria miliaris in Case 36, which have a strong resemblance
to a slug. In the beautiful specimens of Deima this modi-
fication of the form of the body, showing a flat ventral sur-
face, or " foot ", for progression, and a convex hogged back,
is even better marked ; but in Deima instead of three ven-
tral ambulacra there are only two.

The external characters of the typical Holothurian are
conspicuously easy to note. The body is elongate and more
or less cylindrical, tapering at both ends. At one end
(oral pole) we find a large mouth surrounded by a crown of
tentacles, which last, however, are very commonly retracted
within the mouth. At the opposite end (anal pole) is seen
the anus, which is often surrounded with a ring of more or
less calcareous papillae, or " teeth".

The details of the internal structure of the Holothuroi'
dea — the digestive system, the internal respiratory system,
the water-vascular system, the generative system, etc. —
are very clearly shown in the series of dissections in spirit
of Holothuria^ StichopuSy and Mulleria^ in Case 36. The
dissected specimens of Stichopus and Mulleria exhibit
very beautifully a curious feature in the life of these ani-
mals: in the Stichopus the body-cavity is seen to be occu-
pied by a long eel-like fish of the genus Fierasfer, the head
of which lies in the cloaca of the Stichopus : in the Mulleria
the cloaca is occupied by a small crab. At first sight it
might appear as if the fish and the crab were parasites upon
the animal in which they are found, and lived at the ex-
pense of their host ; but that this is not so is proved by the
fact that both the fish and the crab have all their organs of
nutrition, respiration, circulation, excretion, locomotion,
volition, etc., fully and perfectly developed, — a state of

no A Guide to the Zoological Collections in the

things that is 'never found in parasitic animals, which always
show a degradation of some or all of these organs.

The fish and crab are really "commensals^' or mess-
mates with the Holothurians with which they live. " This
living together of two animals is known as * symbiosis '. It
differs essentially from parasitism, in which one organism
preys upon another, the host deriving no benefit but only
harm from the presence of the parasite. In symbiosis on
the contrary the two organisms are in a condition of mu-
tually beneficial partnership". — (Jeffery Parker). The
Holothurian furnishes a safe retreat for the fish and the
crab, while the fish and the crab probably serve the
Holothurian by keeping it clean in some way.

[Another excellent instance of symbiosis is illustrated
in Case i6, where the coralla of Heterocyathus are found
to be tenanted each by a small worm. In this case the
Heterocyathus serves the worm by affording it a safe re-
treat, while the worm returns the service by carrying the
Heterocyathus about from one feeding ground to another,
thus transforming it from a fixed and sedentary into a free-
ly locomotive animal].

The Holothuridea are found at the bottom of all seas
from the surf line to the greatest depths of the ocean.
They live, as is well illustrated in the dissected speci-
mens, upon sand and mud, with which they gorge them-
selves for the sake of the small amount of organic matter
(remains of dead animals, living animalcules, etc.) that
is contained in its interstices, very much in fact as earth-
worms do.

The Holothiiroidea are represented in the exhibited col-
lection by the following genera from the Indian area: —

(i) Deep-sea forms — Deinia, Orphnurgus, Pannychia,
Laetmogone, Euphronides, Psychropotes, Benthodytes,
Apodogaster ; Eupyrgus, Ankyroderma, Trochostoma :

{2^ Shallow -water and Reef forms — Synapta, Haplodacty-
lus Caudina ; Cucumaria, Colochirus, Ocnus, Thyone,
Thyonidium, Stickopus, Holoihuria, Bohadschia, Mulleria.

Invertebrate Gallery of the Indian Museum. iii

PHYLUM VI OF THE CCELOMATA.

MOLLUSCA.

The Mollusca occupy the long double row of desk-cases
that traverses the middle of the gallery, as well as the
three short rows of desk-cases that run at right angles to
the first — one at each end of it and one bisecting it.

A typical Mollusk — e.g., a Gastropod — is an animal
with a soft non-segmented body protected by a hard
calcareous shell into which, as into a house, the body can
in most cases be completely withdrawn. In the typical
Mollusk we can distinguish (i) a well-marked head with
[a) a mouth and a pair of short broad mouth-tentacles
or " lips ", and {b) a pair of long cylindrical cephalic
tentacles, upon some part of which the eyes are usually
carried ; and (2) a body enveloped in a fold of skin or
" mantle ", the under or ventral part of the body being
thickened to form a great solid muscular protrusible foot
for progression, while the thin-walled upper or dorsal
part contains the viscera and is permanently lodged within
the cavity of the shell. The shell is formed by the calci-
fication of the surface layer of the special fold or out-
growth of the wall of the dorsal part of the body already
spoken of as the " mantle " or pallium, which in the
typical mollusk completely envelopes the body and foot
like a cloak or skirt. The space between this mantle-
cloak and the body is known as the " mantle-chamber" or
"sub-pallial space'': it contains the breathing-organs, and
receives the openings of the excretory organs, and often of
the reproductive organs also. A good simple example of a
molluscan " foot ", " mantle", shell, and " mantle-chamber"
is furnished by the common Limpet, placed above Case
128.

The internal structure of a typical mollusk may "be
studied in the dissections of the large Snail placed above

112 A Guide to the Zoological Collections in the

Case 179, in which there can be seen (l) the alimentary
canal coiled and embedded in a dark digestive gland or
" liver", and ending in the fore-part of the mantle-chamber
on the right side ; (2) the two-chambered heart into which
the blood-vessels that branch' over the breathing-organ
are collected ; (3) the excretory organ or kidney running
alongside the great blood-vessel that proceeds to the
heart; (4) the coiled reproductive glands with their ducts
and accessory glands (in one case a part of the duct is
full of eggs); (5) the nerve-ganglia, collected in three pairs
in the vicinity of the front part of the alimentary canal^
with the nerve-cords that connect the ganglia. There
should also be noticed opening into the front part of the
alimentary canal, (6) the arborescent salivary glands with
their long ducts, and (7) the sack containing the " odonto-
phore '\ an organ to be presently described. All these
parts can be easily seen in the dissections.

The Mollusk shell, as already stated, is formed by the

calcification of the superficial layer of the mantle, and

therefore increases in size as the mantle grows. The

variations in the shape of the shell will be afterwards

considered.

The Molluscan "foot" is a characteristic organ of
the highest importance : it is often divided by constric-
tions into three distinct parts, — a front, a middle, and a
hind part, known respectively as "propodium", " meso-
podium", and " metapodium ", which may undergo various
modifications and suppressions.

Another characteristic Molluscan organ is the "tongue '*,
or " odontophore ", or "radula". It is a horny strap,
the upper surface of which is generally covered with
small sharp teeth arranged in rows like a rasp : in use
it is worked backwards and forwards by special muscles,
and in repose it lies coiled up in a sheath at the floor of
the mouth. The typical odontophore is well shown in the
dissected specimen of the Limpet above Case 128, in which
it is of enormous length.

Invertebrate Gallery of the Indian Museum. 113

The sexes may be distinct, or may be united in the
same individual, as they are in the Land-snails. Repro-
duction takes place by means of eggs, which in the case of
many marine Moliusca are glued together in masses or
capsules of remarkable form. Several of the most peculiar
forms of these egg-caps ules are shown on the stand that
rises above the desk-cases, and among them a curious
form shaped like a ruff and much resembling a Sponge or
a Sea-mat in general fabric,

Moliusca are found in all situations — on dry land at
all elevations, in swamps, rivers, lakes and ponds, on
the reefs and rocks of the sea-shore, at the surface of the
open seas, and in the deepest abysses of the ocean.

The Molluscan phylum is divided by Professor Ray
Lankester, whose classification is here followed, into two
great branches, namely, (i) the Glossophora, in which there
is a distinct head provided with an odontophore ; and (2) the
Lipocephalay in which neither head nor odontophore are
present.

I. 2. 3. MOLLUSCA GLOSSOPHORA.

This branch includes three Classes, namely, (i) the
Gastropoda^ (2) the Scaphopoda, and (3) the Cephalopoda,
which are distinguished from one another chiefly by the
form of the foot.

I. GLOSSOPHORA GASTROPODA.

[Ciisiis l26Jl-168aC, ani) i-J13£].
In the Gastropoda, of which the Garden Snail is an
example, the foot has usually a broad flattened sole-like
surface for progression. A shell is usually present, and
has the form of a cone, which may be simple, but more
commonly is coiled in a spiral — sometimes of many whorls.
The direction of the spiral is most usually from right to
left. The simple cone is seen in the Limpets [Patella),
Case 128: an elongated tube with an indefinite loose
spiral coil occurs in Siliquaria and Vermetus, Case 140X :

114 A Guide to the Zoological Collections in the

the close produced spiral is shown in Turritella^ Case
140X, and the close plane spiral in Rotella, Case 131 A, and
Marisa 148 A. All manner of intermediate forms occur.

The mouth of the shell, which is polished and often
thickened and everted, is known as the '' peritreme", and
the axis round which the shell is coiled is the "columella",
each turn of the coil being called a " whorl ". The
columella is sometimes closed below by the peritreme,
but sometimes remains open, the opening being known as
the " umbilicus '\

The mouth of the shell can commonly be closed by a
horny or shelly plate known as the '' operculum ": this is
secreted by the upper surface of the hinder portion of the
foot, or metapodium.

There are two subdivisions of this very large Class—
(i) the Gastropoda Jsopleura, in which the body with all
its contents is bilaterally symmetrical ; and (2) the Gastro-
poda Atiisopleura, in which only the head and foot are
bilaterally symmetrical, while the visceral mass and
mantle are twisted completely over to the right side, the
intestine ending alongside or above the animal's head.

a. GASTROPODA ISOPLEURA.

[Cases I26jl-X26f ].

The principal Order of this sub-Class is that of the
Polyplacophora or Chitons.

The Chitons are distinguished among all Gastropoda
by the nature of the shell, which consists of eight imbricat-
ing plates arranged in a row, and deeply immersed in the
rough leathery mantle. They are common inhabitants of
the rocks of all shores, and are well represented in Case
126A-B. The sexes in the Chitons are distinct.

b. GASTROPODA ANISOPLEURA.

The anisopleurous or asymmetrical Gastropods are
subdivided into four Orders according to the nature of
the breathing organs, namely, (i) the Zygohranchia
with a pair of gill-plumes ; (2) the Azygobranchia with

Invertebrate Gallery of the Indian Museum. 115

only one gill-plume — the right— functionally developed;
(3) the Opisthobranchta, in which the gill-tuft, often
uncovered by the mantle, is placed often on the after end
of the body and always behind the heart ; and (4) the
Pulmonata, in which the free edge of the mantle is fused
with the body-wall so as to convert the mantle-chamber
into a closed sack, open only in front, which is used as a
lung.

i. GASTROPODA [ANISOPLEURA] ZYGOBRANCHIA.

[(Ea0«0 I26ar— I29f ].

The Zygobranchia are characterised by the possession
of a pair of gill-plumes, by the absence of special genital
ducts, and by the large simple cap-like shell. The Order
includes three families of herbivorous marine littoral mol-
lusks, namely, (i) the Haliotidx ox Earshells, (2) the Fis-
stirellidas ox Key-hole Limpets, and (3) ihePatellidxox true
Limpets : all three are widely distributed, the Ilaliotidse
being most numerous in the Australian region, and the
Fissurelidse in South America. All three families are well
represented in Cases 126C — 129B. The sexes in the
Zygobranchia are distinct. In the true Limpets the
gill-plumes are rudimentary, and the functional breathing
organ is a fringe at the circumference of the mantle — see
the preparation above Case 128.

ii. GASTROPODA [ANISOPLEURA] AZYGOBRANCHIA.
[(Eases l29ar-lC6|5].

In the A zygobranchia owing to the torsion of the visceral
mass to the right the important organs (gill-comb, kidney,
etc.) on the left side have atrophied and disappeared
The sexes are distinct, and special genital ducts are
present. A large spiral shell, often of many whorls, is
present, and the mouth of it is often closed by a horny or
stony operculum. The Order is a very large one and
includes both terrestrial and freshwater as well as a

H 2

Ii6 A Guide to the Zoological Collections in the

vast number of marine forms : it is divided by Professor
Ray Lankester into two sections— a larger section, knovi^n
as Reptantia or Creepers, in which the foot forms a disk
for crawling ; and a very much smaller section, known as
Natantia or Swimmers, in which a part of the foot forms
a fin-like swimming organ.

REPTANTIA.
There are three sub-Orders of crawling Azygobranch
Mollusks, namely, (i) the fiolochlamyda, in which the
free edge of the mantle is simple or very slightly produced,
and the lip of the shell therefore unnotched or only
slightly notched ; (2) the Pneumochlamyda, in which the
mantle-chamber forms a lung-sack, as it does in the
Snails, with which, however, they must not be confused ;
and (3) the Siphonochlamyda, in which the edge of the
mantle forms a long tube or siphon which notches deeply
the lip of the shell.

a, GASTROPODA AZYGOBRANCHIA HOLOCHLAMYDA.

[aia0£0l29(E-l48Jl].

Lip of shell not channelled, or only slightly so [Ceri-
thiidse). The animals are mostly vegetarian: many live
in the sea, many in salt and brackish swamps, some in
freshwater, and some on dry land. They are grouped
by Professor Ray Lankester into 19 families, 18 of which
are thoroughly well represented in the exhibited collection.

1st Family, Trochidae [Cases 129C 132C].

This is a very large Family of marine gastropods^ the
species of which are commonly found not far from low-
water mark. They feed principally on sea-weed, and are
universally distributed. A few species live in the depths
of the ocean. The shells are mostly pyramidal or turbinate,
and are furnished with an operculum which may be either
stony or horny. Most of the genera of this large family
are represented in Cases i2gC — 132C.

2nd Family, Neritidse [Cases 133 A — 134A].

Invertebrate Gallery of the Indian Museum. 1 1 7

The members of this family are almost entirely inhabit-
ants of the tropics : most of them are marine and littoral,
but some [Neritella, Navicella) occur in rivers, and some
are amphibious in certain estuarine localities. They are
all herbivorous. Specimens of all the known genera are
to be found in Cases 133 A — 134 A. The shells are cap-like,
the last whorl being large, and the preceding whorls
being small and often more or less absorbed. The oper-
culum is either horny or may be a thin calcareous plate.

3rd Family, Pieurotomaridse [Case 134A].

A small family of herbivorous gastropods found for the
most part among the coral-reefs of the Indo-Pacific. The
shells of Stomatia have a resemblance to those of Haliotis.

4th Family, ScalaridsB [Case 134B-C].

The members of this small family are predaceous, and
though widely distributed occur in greatest abundance in
Eastern Seas. The shell, which is closed by a horny oper-
culum, forms a most elegant tapering spiral, the whorls of
which are ornamented by numerous equidistant cross-ribs.
Scalaria secretes a purple fluid when molested.

5th Family, JanthJnldge [Case 135A].

The Janthinidse or " Violet Snails" are predaceous
mollusks which live at the surface of the open oceam
being kept afloat, as by a buoy, by a long cluster of air-
vesicles developed on the " foot." The shells are commonly
cast ashore on the coasts of India after strong southerly
gales. Janthina is able to secrete a purple fluid, by which
the thin shell is beautifully dyed. Observe the spirit
specimen of a female Janthina above Case 135, showing
the vesicular float-like foot, with the egg-capsules sus-
pended from its under surface.

6th Family, Cerithldse [Cases 135B— 136C],

Of the species of this large family some are marine,
some, as Pyrazus and Telescopimn, inhabit mangrove
swamps and brackish marshes, and a few [Cerithidea)
are amphibious. Some species of Cerithiuniy secrete a
green fluid when molested. The shells have the form

ii8 A Guide to the Zoological Collections in the

of long pointed many-whorled spires, the lip "of which is
often notched and channelled, and they are closed by a
horny operculum.

yth Family, MelanidSB [Cases 137 — 139B].

A large family of freshwater mollusks abounding through-
out the warmer regions of the world. The shells are
spiral turrets, often of great length, and are usually
covered with a thick dark-coloured epidermis, and closed
by a horny operculum. Very commonly the top of the
spire is eroded and decollated, but often [e.g.^ Faunus)
is quite perfect. The animals appear to prefer muddy
water, and are herbivorous.

8th Family, Pyramideilidse [Cases 140A, B].

The shells in this family are most usually long acutely-
pointed many-whorled spires, with the lip often notched
and slightly channelled. The animals are marine, and
are probably predaceous. Operculum horny.

9th Family, TurrltelUdse [Case 140X].

The " Screw Shells " are marine and are widely dis-
tributed. In the Turritellidx proper the shell is an
elongate beautifully tapering spire: in the Cdscid% it is a
spiral disk in the young stage, but in the adult, by the loss
of the spire, it becomes a simple tube : in the Vermetidse
also it becomes in the adult a loosely and irregularly
twisted tube, much like a worm-tube. The shells are
usually furnished with a horny operculum.

loth F'amily, Xenophoridse [Case 140X].

The " Carrier-shells " are marine, and have the remark-
able habit of strengthening and protecting their own shells
with the dead shells of other species of Mollusca, the
protective pieces being arranged with beautiftd regularity
round the edjjes of the whorls. The foot is also remark-

Invertebrate Gallery of the Indian Museum. 119

able in being cylindrical and in being divided into two
portions — an after portion which carries the horny oper-
culum, and a front portion on which the animal hops.

nth Family, Naticidae [Cases 140Y — 141 A].

This is a (large and geologically ancient family of
predaceous marine mollusks. The animals have a small
head, and an enormous foot for burrowing, and they are
usually blind. The shells generally have the last whorl
of great size and the spire small, and are either globose
or ear-shaped : the operculum is either w^ell developed
and stony, or horny and rudimentary. The Naticidge are
of universal distribution and are very abundant in tropical
seas,

i2th Family, Marsenidge [Case 141 A].

A small family of carnivorous marine mollusks in
many respects resembling the Naticidx. The shells,
which are very fragile and are often covered with an
epidermis, or are sometimes hidden by the foot, resemble
those of Sigaretus among the Naticidx^ but have no
operculum.

13th Family^ Acmseldae [Case 141 B].

The Acmasidx are known as "False Limpets" from
the resemblance of their shell to that of the Limpets. The
animal, however, differs from the Limpet in having a single
true gill-plume on the right side of the neck ; whereas in
the true Limpet the gill-plumes are minute rudiments
placed symmetrically one on each side of the neck, and
the functional gill, as may be observed in the spirit speci-
men above Case 128, consists of a fringe of filaments
hanging from the inner surface of the mantle throughout
its whole circumference. The Acmgeidce are widely

« 20 A Guide to the Zoological Collections in the

distributed, and in habit and manner of life resemble the
true Limpets.

14th Family, Capulidse [Cases 142A, B].

The Capulid% are known as " Cup and Saucer Limpets".
They also resemble the true Limpets both in habit and
in form, but differ from them in having a single true
gill-plume, well developed and on the right side of
the neck, as among the Acmceidae. The shell differs
from the simple cap-like form of the Limpet and False
Limpet in having either the aperture partly covered in
behind {e.g^ Crepidula), or the dome furnished with a
more or less complete shelly cup (the rudiment of a
columella) for the special protection of the viscera [e.g-i
Crucibulum).

15th Family, Littorlnidse [Cases 143 A — 145B].

The Periwinkles form a very large and very widely
distributed family of herbivorous gastropods, the great
majority of the species of which are marine and littoral,
often living above high-water mark. The shells are
turbinate with the lip smooth and unnotched : in some
species they resemble Trochus shells, from which, however,
they may be distinguished by the dull (non-nacreous)
interior, — the shells of the Trochidx being always bril-
liantly pearly (nacreous) within.

Hydrobia and its alliance, and Assiminea and its
alliance, live in brackish and fresh waters, some species of
these genera, like the true Periwinkles, being amphibious.
The shells of the Littorinidx are closed by a horny oper-
culum.

i6th Family, Paludinid36 [Cases 145C— 147A].

The "River Snails" resemble the Periwinkles. They
inhabit rivers, lakes, ponds, and marshes throughout the
northern hemisphere. They are viviparous. The shells,
which generally have the spire produced, are thin, are

Invertebrate Gallery of the Indian Museum. I2i

covered with a dark epidermis, and are closed by a horny
operculum.

17th Family, ValvatJciae [Case 147B].

The Valvatidx are a small family of pond-snails,
occurring chiefly in the temperate parts of the northern
hemisphere. The animal is remarkable — see the enlarged
drawing in Case 147B — in having its gill-comb exposed.
The shell, which is covered with epidermis, is a spiral,
usually coiled in a nearly horizontal plane, and is closed
by a horny operculum.

i8th Family, Ampullaridse [Cases 147C— 148A].

These are pond and river snails found principally within
the tropics. Although the animal possesses a gill, it also
has a part of the mantle-cavity shut off to form a lung-
sack, so that it can live as well on dry land as it can
in freshwater. The shell is a short spiral covered with
dark epidermis and closed by an operculum which is some-
times stony.

/5. GASTROPODA AZYGOBRANCHIA PNEUMOCHLAMYDA.

[Cases jiE ;a, f , or].

In this sub-Order of crawling Gastropods the gill is
absent, and the mantle-edge is adherent to the body in the
greater part of its extent to form a lung-sack. The
species of this large group are all, like the true snails,
terrestrial, but they differ from the true snails in many
important details of internal organization and also in pos-
sessing an operculum to close the shell. This sub-Order
comprises the three families of the Cyclostomidw, Helici-
nidse^ and Aciculidx.

y. GASTROPODA AZYGOBRANCHIA SIPHONOCHLAMYDA.

[(Eases l48|5~X66f ].

In this sub-Order uf crawling Gastropods the edge of

the shell is notched, or is drawn out to forma long narrow

channel, for the passage of a corresponding process of

the mantle. The animals are almost exclusively marine

122 A Guide to the Zoological Collections in the

and are generally predaceous. The following are the prin-
cipal families : —

ist Family, Strombidse [Cases 148B— 150A].

*' Wing shells" and "Scorpion shells". Among the
members of this family the shell of the adult usually
differs very considerably from that of the young. In the
young it usually has the form of a simple close-coiled
spiral cone, but in the adult the outer lip of the mouth of
the shell generally becomes greatly expanded in the form
either of a simple wing [Strombus), or of a wing festooned
with great spreading curving claws [Pteroceras): a series
of specimens of Pteroceras, in Case 149C, shows this
difference between the young and the adult shell in its
most marked degree. The spirit specimen of Rostellaria
delicatula, placed above Case 150, shows the characters
of the typical animal, with its long snout and its long
cylindrical foot for hopping. Observe the characteristic
small horny operculum in situ on the foot.

2nd Family, Aporrhaidge [Case 150B].

A small family of Wing shells, no member of which is
known to occur in Indian Seas.

3rd Family, Dolidae [Cases 150 C — 15 iB].

" Tun shells", " Helmet shells", " Fig shells".

In this family the shells are large and inflated, with
the whorls ribbed or varicose, and the peritreme deeply
notched in front : they are sometimes remarkably thin and
light, and sometimes {Cassis) remarkably thick and heavy,
especially at the lip. The thick shells of Cassis are used
in the manufacture of cameos.

The animals generally hare a very large foot. In
Dolium and its allies there is no operculum.

4th Family, Tritonidae [Cases 151B — 152C].

" Trumpet shells".

The Tritons are for the most part tropical, and reach
their maximum in the Eastern Seas. The shells have
usually a prominents pire and numerous ribs or varices,

Invertebrate Gallery of the Indian Museum. 123

are often brightly coloured, and are closed by a horny
operculum.

5th Family, Cypriaedse [Cases 153A— 154CJ.

The Cowries are remarkable for their richly coloured
and beautifully polished convoluted shells, which outwardly
appear to consist, in the adult, of a single whorl with the
outer lip remarkably rolled in, the other whorls of the
spiral being almost entirely concealed. In young indivi-
duals, however, the spire is distinct and prominent, and
the outer lip has a simple sharp edge. The animal is nota-
ble for its large foot and for the lobe-like extensions of its
mantle, which fold over the shell from each side, nearly
meeting in the middle line above. The Cowries are
characteristic of tropical seas, especially those of the
eastern hemisphere. An operculum is absent. Observe
the longitudinal vertical section of a Cowrie shell in
Case 154C.

6th Family, Pedicularidse [Case 150B].

This is a very small family, consisting of a few species
of a si ngle genus of small gastropods parasitic on Corals.
In the younger stages the shell of Pedicularia is regular,
but in the adult the degradation resulting from the parasitic
habit leads to marked deformity.

7th Family, Conldae [Cases 155A— 1566].

The ''Cones "are remarkable for their magnificently
coloured shells, and are characteristic inhabitants of the
shallow seas of the tropics, especially of the eastern
hemisphere. They are excessively predaceous, and are
said to be capable of inflicting a dangerously venomous
bite. The shell of the Cone, like that of the Cowrie, often
appears to consist, to outward view, of a single whorl,
owing to the fact that the last whorl envelopes and
conceals the others. The operculum, when present, is
small.

8th Family, Terebridse [Cases 156B-C].
The beautiful " Augur shells " are also characteristic
of the seas of the eastern tropics. The shells are long,

124 A Guide to the Zoological Collections in tJie

slender, polished and acutely pointed, and consist of a
spiral of many whorls.

gth Family, Pjeurotomidae [Cases 157 A-B].
The " Hare-lip shells " although universally distributed
are most numerous in tropical seas. About eighty s[)ecies
are also known from depths of 200 to 2,500 fathoms. In
the typical forms the shell has a long channel for the
siphon, and is deeply cleft in the outer lip near the
" suture", the mantle also having a corresponding cleft.

loth Family, Cancel faridse [Case 157B].

In this family also the majority of the species inhabit
the seas of the tropics. The shell is "cancellated", or
marked with a fine lattice-work of cross-ribs. The animals
are said to be vegetarian.

nth Family, Muricidse [Cases 157C— 160A].

This is a very large family, the constituent species of
which are widely distributed, though most abundant in
warm and tropical seas. The shells are often beautifully
and regularly " variced " or ribbed, the ribs being some-
times foliated and frilled and sometimes ornamented with
rows of long spines. In the animal, an adrectal gland is
highly developed and secretes a colourless fluid, which, on
exposure to the air, turns purple ; and it was from a spe-
cies of Murex that the famous Tyrian purple was manu-
factured.

i2th Family, Bucclnidse [Cases 160A — 162B].

The type genus of this large family — the Common
Whelk [Buccinum) — \s confined to the colder temperate
and the polar seas ; but several of the largest genera — e.g.,
Nassa, Purpura, Ricinula — occur in great abundance in
Indian waters. The shells vary greatly in form ; in many
species they have a large and well-produced spire, but in
some genera — e.g., Purpura, Ricinula, Cuma, Rapana —
the spire is short, being sunk in the last whorl, which is
very large. The species of Purpura secrete a purple dye.

Invertebrate Gallery of the Indian Museum. 125

Observe the peculiar form of the shell of Magilus in Case
162B : Maorilus lives in crevices in growing coral-stocks,
and as the coral spreads, the Magilus^ in order to avoid
being overgrown and buried, continuously lengthens its
shell at the mouth, until at last the shell comes to be
nothing more than a long irregular tube, not unlike a large
worm-tube.

13th Family, Mitridse [Cases 162C — 164B].

The species of this large family are almost exclusively
tropical, and are specially numerous in eastern seas. The
shells are very beautifully sculptured and coloured, and
have generally a long sharp spire. The inner lip of the
mouth of the shell is marked by several oblique folds and
ridges, and an operculum is either rudimentary or absent.

14th Family, Olividae [Cases 164B — 165B].

The shells of the Olividse somewhat resemble those of
the Cypraeidas by reason of their polish and shape, the last
whorl, which is of great size, more or less completely
enclosing and concealing the spire. The inner lip of the
Olive-shell, however, is marked by several prominent
oblique folds, and the outer lip is not rolled in as it is in
the Cowries. The animals of the two families, moreover,
differ in several respects, but most markedly in the
structure of the odontophore. An operculum is commonly
absent.

15th Family, Voiutidae [Cases 165C — 166B].

This family includes the large " Boat-shells " and
" Melon-shells " of the Indo- Pacific shores. It also includes
the small cowrie-like Marginellas, which, however, can
always be distinguished from cowries by the oblique folds
on the inner lip that characterize all the Volute shells.

NATANTIA.

[(Ense 1660^].
In the Section of Swimming Azygobranch Gastropods,
which corresponds to the Order Heteropoda of authors,

126 A Guide to the Zoological Collections in the

the visceral hump is generally reduced in size, while some
part of the foot — usually the middle portion, or mesopo-
dium — is specially developed to form a fin, upon which an
adhesive sucker is commonly found. The shell, when
present, is small and thin, and like the rest of the animal
is transparent, in harmony with the environment. The
animals are pelagic, swimming at the surface of the open
seas in the warmer parts of the world, and in habit are
predaceous. Professor Ray Lankester divides the Sec-
tion into three sub-Orders, namely, (i) the Atlantacea,
in which the visceral hump, mantle, and shell are large ;
and all parts of the foot are well developed, — the whole
form, in short, being not very different from the ordinary
Azygobranch type ; (2) the Carinariacea, in which the
visceral hump, mantle, and shell are small, and the
foot is not demarcated from the rest of the body, except
in its middle portion, or mesopodium, which forms a
large fin ; and (3) the Pterotracheacea, in which the
visceral hump is still further reduced in size, the mantle
rudimentary, and the shell absent, the foot being similar
to that of the Carinariacea, The group is exemplified
in Case 166C, by models and enlarged drawings, and by
some shells and spirit specimens. The last, which are
placed above Case 166C, illustrate the transparency of the
body.

ill. GASTROPODA [ANISOPLEURAJ OPISTHOBRANCHIA.
[ara0t0 167JI-168(E].

In the adult forms of this degenerate Order the foot is
large, and the visceral hump small ; the mantle is always
small and is often entirely wanting, and in correlation
with the condition of the mantle the shell is almost always
more or less delicate and deficient, or is completely absent.
In the larval stage, however, the larval nautiloid shell of
the typical Moilusk is present. The typical gill-plume is
sometimes present unmodified, is in other cases present

Invertebrate Gallery of the Indian Museum. 127

in a modified form, and is sometimes altogether absent :
when present it arises behind instead of beside the heart.
The Opisthohranchia are all marine : the majority are
found either in the tidal pools of reefs, or not far below
low-water mark ; a few are pelagic, inhabiting floating
sea-weed ; and a very few have been dredged from a con-
siderable depth in the ocean. The reef forms, especially
those of the tropical seas, are often of remarkably fantas-
tic beauty of form and splendour of coloration.

In habit the Opisthobranchia vary, many being ex-
tremely rapacious, while others feed entirely on sea-weed.
Several of the tropical forms have the power of emit-
ting— probably for protection against enemies — acrid and
offensive odours ; and the Sea-hare when molested can
secrete an abundant cloud of purple fluid for purposes
of concealment. All these secretions probably come from
glands in the skin. All the Opisthobranchs are herma-
phrodite.

The Opisthobranchs are divided into two sections,
namely, (i) the Palliata^ or Tectibranchiata, in which
the mantle and generally a thin shell are present cover-
ing the breathing-organs ; and (2) the Slug-like Non-
palliata, or Nudibranchiata, in which, in the adult, the
mantle and shell are wanting, leaving the gill-plume, when
it exists, exposed.

/3. OPISTHOBRANCHIA PALLIATA.

[OtaseB 167JI-C!!].
There are two sub-Orders of mantle-bearing Opis-
thobranchs, namely, (i) the Ctenidiobranchia, which have
a functional gill-plume and usually a thin shell ; and (2)
the shell-less Phyllidiobranchia, in which the place of
the gill-plume is taken by a pair of fringes on the inside
of the mantle. The Phyllidiobranchia, which include but
one small family, are represented in the Case by drawings.
The Ctenidiobranchia, which comprehend (i) the Torna-
ellida.', (2) the large family of the Bullida' or " Bubble

12

8 A Guide to the Zoological Collections in the

shells", (3) the Aplysiidse or Sea-hares, and (4) the
Pleurohranchida; or " Umbrella- shells", are illustrated
in Cases 167 A — C by spirit specimens, drawings and
models, and by a large series of shells. On comparing
the shells of these four families, we find a regular degra-
dation from the stout operculated spiral shell of Torna-
tella to the thin light simply-rolled shell of Bulla, which
in life is largely concealed by the side-lobes of the foot ;
and thence, through the simple calcareous disk of Um-
brella, to the paper-like plate of the Sea-hare, which in
life is hidden in a fold of the mantle.

a. OPISTROBRANCHIA NON-PALLIATA.

[€it0£0 168<|1— €].

In the Slug-like non-palliate or naked-gill forms the
mantle, and consequently the shell, are absent in the adult,
and the gill-plume, therefore, when present, is exposed.
Professor Ray Lankester subdivides the group into three
sub-Orders, namely, (i) the Pygohranchia^ in which the
gill-plume has the form of a coronet of tentacles round the
anus ; (2) the Ceratonota, in which there is no gill-plume,
and the back is covered with hollow filaments, or "cerata",
which no doubt assist in respiration ; and (3) the Haplo-
7norpha, comprising a few simple degraded more or less
worm-like forms which are only recognised as Mollusks
by the possession of the molluscan odontophore. This
section is well represented by models in Cases 168A — C.
and by some fine spirit specimens, from the Andama n and
Laccadive Reefs,placed above the Case.

iv. GASTROPODA [ANISOPLEURA] PULMONATA.

\j^-&&ZQ I— t)iii at §outh cub, anf) ix to .\b at Jlorth t\\ii

of (!BaUci-ii].

This great Order, of which about 10,000 species are
known, includes the Snails and the Slugs, the great

Invertebrate Gallery of the Indian Museum. 129

majority of which are terrestrial herbivorous animals,
though some of the Snails, eg., Limnxus, Planorbis^ etc.
live in fresh water, and a few Snails, and Slugs also, live
on rocks between tide-marks in the warmer seas. All
however, whatever their habitat, breathe not by means
of a gill, but by means of a " lung-sack" which is formed
by the mantle-chamber, the edge of the mantle being
fused with the dorsal wall of the body, except at one point
in front for the admission of air. Even in those aquatic
forms tliat breathe air dissolved in water the breathing-
organ is the " lung-sack", into which water, instead of
air, is admitted.

In the majority of the Pulmonates a well developed
shell is present, but is never closed by an operculum ; in
the Slugs, however, \\\t shell is a rudimentary plate which
is generally hidden (" internal shell ") and in the marine
slugs [Onchidiiini] there is no shell at all.

Ihe Pulmonata must be carefully distinguished from
the group of terrestrial Azygobranchs — the Pneumo-
chlamyda — which also breathe air by m.eans of a lung-sack
formed by the closure of the mantle-chamber. In the
Pulmonata^ or Snails and Slugs, the odontophore is armed
with numerous small and equal-sized denticles, the sexes
are united in the same individual, and the shell when pre-
sent, is never closed by an operculum. In the Pneumo-
chlamyda, on the other hand, the teeth on the odontophore
are in a few series of unequal size, the sexes are
distinct, and an operculum is developed on the back of
the foot. The Pulmonata are divided into two sub-
Orders, namely (i) the Basonimatophora, including the
two families of the freshwater Snails [LtmnxidcB) and the
marine Auriculidx, in which the eyes when present are
placed at the base of the cephalic tentacles ; and (2) the
Stylomviatophora, including the two great terrestrial fami-
lies of the Snails and the Slugs [Helicidx and Limacidx)
and the small family of estuarineand marine Slugs {Oncid-
iid(s), in which the eyes are borne at the summit of the
cephalic tentacles. The Pnhnouata are well represented

I

130 A Guide to the Zoological Collections in the

in the two series ofCases I to VIII at the south end of the
Gallery, and IX — XV at the north end of the Gallery, by
a great variety of species from all parts of the world and
from all elevations,

2. GLOSSOPHORA SCAPHOPODA.

[OCaee 169JI].

In the very small Class of the Scaphopoda, or " Tooth-
shells ", the foot body and mantle are much elongated :
the opposite edges of the mantle meet and unite below
the foot to form a tube, on the outside of which a long
cylindrical pointed tusk-like shell is developed. The shells,
in fact, much resemble the calcareous tubes of certain
marine worms. The Scaphopoda, which are represented
in Case 169A by specimens of Dentalium, Cadulusy and
Entalis, live in the bed of the sea, burrowing in the sand
with their long scoop-like foot.

3. GLOSSOPHORA CEPHALOPODA.

[(Ea0£0 X69f — 171(E].

In this Class, the members of which are all marine and
freely locomotive, the foot is modified principally for
swimming, but also in part for prehension and for walk-
ing. Of the three regions of the foot the front region
(propodium) is fused with the head and is usually split
into fleshy prehensile " arms " of varying length ; the
middle region (mesopodium) is expanded on each side to
form either a pair of wings (epipodia), or, by the inrolling
of the wings and the apposition or actual union of their
edges, a short funnel ; while the after region (metapodium)
is small or absent. The mantle is usually well-developed,
and encloses a deep pocket-like mantle-chamber ; in one
group of Pteropods, however, it is altogether absent. The
shell varies ; when present it is always light, and is often
entirely concealed in a fold of the mantle.

The Cephalopoda are divided by Professor Ray Lan-
kester into two branches or sub-Classes, namely (i) the

Invertebrate Gallery of the Indian Museum. 131

Pteropoda in which the epipodia, or lateral flaps of the
middle region of the foot, are in the form of wings or
paddles ; and (2) the Siphonopoda in which the lateral
flaps of the mesopodium are rolled in and united to form
a funnel, or siphon, which also serves primarily for loco-
motion.

a. CEPHALOPODA PTEROPODA.

[€a0e I69i].

The Pteropods or Sea-butterflies are small hermaphro-
dite Mollusks usually found in swarms at and near the
surface of the open ocean, paddling or flitting by means of
their wing-like epipodia. They are divided into two
Orders, (i) the Thecosomata, in which there is a mantle
and a thin glassy casque-shaped or mask-shaped shell, and
(2) the Gymnosomata, in which a mantle and consequently
a shell are absent. In the latter group the "arms", or
tentacle-like processes of the forefoot, are fairly well
developed and carry suckers, resembling, but on a small
and scant scale, those of the Cuttle-fishes. The dead shells
of the Thecosomata often accumulate in extensive beds at
the bottom of the Ocean, forming the deposit known as
Pteropod-ooze. The Pteropoda are illustrated in Case
i6gB, by shells, models, and enlarged drawings.

b. CEPHALOPODA SIPHONOPODA.

[OEasi;© 170^— 171(E],

To this important sub-Class, which includes the largest
and most highly organized members of the Molluscan
phylum, — e.g.^ the Nautilus, the Cuttle-fishes, the Squids,
and the Octopodes — the name Cephalopoda is commonly
confined.

As in the Pteropods, the fore-part of the foot is fused
with the head, and is split up into prehensile processes or
*' arms '\ which, however, are not only more numerous — at
least eight or ten in number— but are vastly more highly
developed. The middle portion of the foot, however,

I 2

132 A Guide to the Zoological Collections in the

though equally important in function, is so far as size is
concerned, subordinate: it. has the form of a funnel or
siphon (whence the name of the sub-Class), through
which the water taken into the mantle-cavity is forcibly
expelled for the purpose of locomotion.

The mantle is very complete and very muscular ; it
encloses a wide and deep mantle-chamber, in which the
gills are placed, and into which the intestine and the
excretory and reproductive organs open.

Except in the Octopodes, a true shell secreted by the
mantle is present, and although sometimes, e.g., Nautilus,
the shell encloses the body, it usually is itself enclosed and
entirely concealed in a dorsal fold of the mantle, and
becomes an "internal shell": in this case it is sometimes,
as in the Squid, a rudiment of quill-like form and paper-
like consistency.

The Siphonopods possess, besides the characteristic
odontophore, a pair of horny or calcareous jaws, shaped
like a parrot's beak, specimens of which are shown in
Case 170. The sexes are distinct.

The spirit specimens and dissections of a common Indian
species of Cuttle-fish, placed above Case 170, give a good
illustration of the Cephalopod type.

An examination of this series shows the animal to
consist of a somewhat rounded head, and an oval or
conical body, the shape of which is determined by the
thick fleshy mantle. The skin both of the head and body
is thickly set with large pigment-ceils, or " chromato-
phores", the play of which in life leads to transient
chameleonic changes of colour.

The edge of the mantle projects round the base of
the head like a collar, the intervening space being the
entrance into the mantle-chamber. From the head S2:)ring
the long fleshy prehensile arms, or prolongations of the
fore part of the foot : these are ten in number, and are
beset on their inner surface with most beautifully formed,
cup-shaped, cartilaginous suckers arranged in rows. In

Invertebrate Gallery of the Indian Museum. 133

the centre of the space enclosed by the bases of the arms
is the mouth with its great parrot-like beak. On each side
of the head is a large and very perfect eye, and in the
space behind and between the eyes is the "siphon".

Along each side of the oval body is a fold of the
mantle which acts as a fin.

If we cut the body down the antero-dorsal surface — as
has been done in one of the exhibited specimens, we come
upon the shell or " cuttle-bone ": it lies immediately
beneath the skin in a closed cavity formed by an over-
growth of the mantle, and has the form of a light oval
plate.

If we open the body from the base of the siphon down
the hinder surface, we enter the mantle cavity, in which is
seen, on each side, a large gill-plume (coloured in the
specimen), and in the space between the gill-plumes the
compact globular mass of the viscera, held together in a
thin but tough bag. On dissecting this off — the exhibited
specimen is a male — we see on the observer's right the
reproductive organ, and its duct opening not far from the
base of the siphon; on the left the stomach, much con-
cealed; and in the middle line the ink-bag, with its duct
running alongside the intestine, and ending beside the
vent at the base of the siphon. The other viscera apparent
are the renal organs : these conceal the heart and great
blood-vessels, which lie behind them, but leave unconcealed
on each side the great globular dilation of the vein at the
base of each gill-plume.

The secretion of the ink-bag, which is known as sepia,
is copiously ejected into the water by the cuttle-fish when
molested, in order to cover its escape.

Cuttle-fishes are found in all seas, in greatest
abundance near shore, but sometimes at the surface of the
high seas, and sometimes in the depths of the ocean.
Their locomotion is effected either by means of the
'arms", on which the animal walks head downwards, or
by swimming. Some cuttle-fishes, as the Sepia, can

134 ^ Guide to the Zoological Collections in the

certainly swim forwards by the undulation of the side-flaps
of the mantle ; but the typical and characteristic motion
is by a series of jerks backwards, this being effected by
the forcible expulsion through the siphon— the mantle
being kept closely applied to the body so as to close the
mantle-chamber in front — of the water contained in the
mantle-chamber.

Cuttle-fishes are highly rapacious, and some species
reach such an enormous size as to be dangerous even to
man.

The curious bunches of eggs of Sepia are shown above
Case 170. The remarkable " hectocotylus arm", or arm
charged with packets of sperm-cells, which the male
sheds into the mantle-chamber of the female, is shown
ready for detachment in the model of Argonauta, in
Case 171.

The siphonopodous Cephalopoda are divided into two
Orders, namely (i) the Tetrabranchiata in which there are
two pairs of gill-plumes, and (2) the Dibranchiata, in
which there is a single pair. The Tetrabranchiata are
represented by the single existing genus Nautilus
drawings and shells of which are shown in Case 170.
The shell of the Pearly Nautilus, as may be seen in the
vertical sections in the Case, consists of a plane spiral of
many chambers, of which only the last one is inhabited by
the animal, the others containing only air. The series of
chambers represent stages in the growth of the animal,
each chamber having been at one time inhabited, and
having been deserted and shut off as the animal outgrew it :
the whole series is connected, as can be seen in the sec-
tion, by a calcareous tube, known as the " siphuncle ",
which traverses the middle of each chamber and keeps the
smallest and earliest formed chamber in communication
with the largest and latest formed. The animal of Nautilus
differs from all other existing Siphonopoda in the following
among other particulars : — there are two pairs of gill-
plumes ; the processes of the fore-part of the foot are not
sucker-bearing " arms ", but are bunches of sheathed ten-

Invertebrate Gallery of the Indian Museum. 135

tacles ; the halves of the funnel, or siphon, are not united'
but are only placed in close apposition, so that the siphon
appears to be fissured ; and there is no ink-bag.

The Dibranchiata include all the existing Siphonopods
with the exception of the Pearly Nautilus. In all of them
the gills are a single pair, the processes of the propodium
are sucker-bearing arms, the halves of the siphon are
united to form a complete tube, an ink-bag is present, and
the shell, when it exists, is " internal ", as already explained.

The Dibranchiata form two sub-Orders, namely (i) the
Decapoda (Sepias and Squids) in which the '' arms " are
ten in number and an internal shell is present, and (2) the
Octopoda (Octopus and Argonaut) in which the " arms "
are eight in number and a true shell is absent.

In Cases 170C-171C there are life-size models,
representing the chief types of both sub-Orders, along
with explanatory drawings, and specimens of the " internal
shells " of Spirula, Sepia and Loligo. The shell of
Argonauta (the Paper Nautilus), specimens of which
also are exhibited, requires a word of explantion. It
is not formed by the mantle, that is to say, is not a
true shell. It is found in the female only, and is secreted
by two of the " arms", which are specially dilated, and are
closely applied to the body to hold the shell on.

The large drawing of the female Argonaut in Case
171C shows the nature of the dilated "arms", and their
relation to the body in life. Observe that the male of
Argonauta, models of which are shown, is much smaller
than the female, and is, like all other Octopoda, shell-less.

4. MOLLUSCA LIPOCEPHALA.

(Lamellibranchia : Pelecypoda).
[i^sk €as£5 172-179].

The Lipocephala, or Lamellibranchia, or Bivalves,
differ from all other Mollusca (i) in the non-development
of the head, and (2) in the absence of the odontophore.

136 A Guide to the Zoological Collections in the

In this large and uniform Class, the body is compressed and
is enclosed in a bivalve shell. The two halves of the shell
are right and left, and are articulated across the back of
the animal by a spring-hinge formed by interlocking teeth
and elastic ligaments; they can, with few exceptions,
be widely separated along the free or ventral surface, but
can also be kept tightly closed by a special muscle or,
more commonly, pair of muscles — the " adductor muscles
of the shell " — which stretch across the upper part of the
Javity of the shell from one valve to the other.

The shell as usual is secreted by the superficial layer
of the mantle, and the latter, therefore also consists of two
lobes which line and are more or less adherent to the
corresponding valves of the shell, the line of attachment
being known as the 'pallial line".

Between the two mantle-lobes lies the body, which
consists of a dorsal mass containing the viscera, and of a
large muscular tongue-shaped or hatched-shaped "foot".

Ihe space between the body and the mantle, on each
side, is the mantle-chamber : it contains the gills, which
have the form of delicate plates or leaves, instead of
plumes. There is a pair of gills on each side. Immediately
in front of the gills, on each side, is usually found a pair
of small flaps very similar in appearance to the gills,
from which they seem to have been derived : these are
the labial palps, and are used for drawing food towards
the mouth which lies between them in the middle line.
The lobes of the mantle are often, like the valves of
the shell, separate from one another, so as to gape when
the shell is opened \ but just as often they are more
or less united together beneath the foot — a chink, however,
being left for the protrusion of the latter organ — thus
closing the mantle-chamber below. When the mantle-
chamber is thus closed, the lobes of the mantle grow out
behind to form two retractile tubes, or "siphons", which
are sometimes of great length. These tubes are placed
one above the other, the lower one (inhalant, incurrent or
branchial siphon) admits water, containing air and the

Invertebrate Gallery of the Indian Museum. 137

microscopic particles on which the Bivalve feeds, into
the mantle-chamber ; and by the upper one (exbalant,
excurrent, or anal siphon) the effete water, charged with
excreted waste, leaves the mantle-chamber. Even in
those Bivalves in which the mantle-lobes are separate
beneath the foot the existence of these two channels —
incurrent below, and excurrent above, can be demon-
strated, although there are no tubular siphons, but only
two slight folds of the posterior edge of the mantle
separated by a limited line of cohesion. It is only in
a few forms [e.g., the Oysters, etc.) that no definite
siphons occur. When the mantle-lobes are separate
their thickened edges are often fringed with tentacles,
and are sometimes furnished with a row of eyes (see
the specimen of Avnissiitni mounted in spirit above Case
179). The tentacles are often confined to the posterior
edge of the mantle, where they surround the incurrent
orifice (see the specimen of the Fresh water Mussel above
Case 173).

As in other typical Molhisca, the intestine, the excretory
organs, and the reproductive organs open into the mantle-
chamber, which also in the Bivalves sometimes serves as a
brood-pouch in which the eggs are hatched.

The sexes among the Bivalves are sometimes separate,
and are sometimes united in the same individual. In the
latter case, as in some Oysters, the male and female ele-
ments may be matured, not at the same time, but at
different seasons.

The nature of the Lamellibranch shell should be studied
in the several preparations in Case 172 A.

The " valves " are, as already stated, right and left :
they are usually, though not always, equal and symmetrical,
and are often covered with an outside skin, or epiderm, of
varying thickness.

In each valve we find, typically, a turned-in beak, or
" umbo ■", which generally looks forwards and marks the
front of the contained animal : the usually short and blunt
portion of the shell below the umbo is therefore the front

138 A Guide to the Zoological Collections in the

end, and the usually long and more acute portion of the
shell is the posterior end. The free edge of the shell cor-
responds with the ventral surface of the animal, while over
the back of the animal the valves interlock along w^hat is
known as the "hinge-line''.

This interlocking is effected by means of "teeth", of
which there are typically three, or three groups, one (or a
group) immediately below the umbo known as " cardinal
teeth", and two (or two groups) of " lateral teeth " placed
respectively before and behind the cardinal. Any or all of
these, however, may be absent. The hinge becomes a
spring-hinge by the action of certain elastic ligaments the
principal one of which passes across, from valve to valve,
behind the umbo, usually on the outside. When, by the
muscular efforts of the animal, the shell is closed, the hinge-
ligament is put upon the stretch ; and when, therefore, the
muscular effort is relaxed, the tension on the ligament is
relieved, and the shell springs open : so that in repose the
shell always gapes.

On the inside of each valve, which is almost always
polished, we usually find certain constant impressions,
namely the pits of attachment of the adductor muscles, and
the line of attachment of the mantle — " pallial-line ".
These should be studied in the series of prepared speci-
mens in Case 172 A.

Notice that in one type the palliaUline has an unbroken
sweep from the anterior to the posterior adductor, while in
another type the sweep is broken by a deep bay — the
" pallial sinus " — which lies below the impression of the
posterior adductor and marks the situation of the retractor
muscles of the siphons.

The Lamellibranch " foot " is usually tongue-shaped,
or hatchet-shaped, and of some size. It can be protruded
between the valves of the shell and used for creeping. In
a few cases — e.g., Niicula — it forms a broad " sole " for
this purpose. In some forms — e.g., the Cockles — it is
curved and is used as a jumping-pole, the Cockle being able

Invertebrate Gallery of the Indian Museum. 139

to make the most surprising leaps. In a few forms — e.^.^
the Razor-shells — it is a long pointed cylinder used for
boring in the sand. In many sessile forms—^.^., the true
Mussels — the foot is provided with glands, known collect-
ively as the "byssus gland", the secretion of which, tough-
ening on exposure to water, forms a bunch of silky
threads — the byssus — by means of which the animal anchors
or permanently attaches itself. In the Oysters the foot is
altogether absent.

Bivalves are all aquatic, and though there is a large
number of nearly similar freshwater forms, the great bulk
of the Class is marine, the species occurring at all depths
and in all situations.

Their typical habit of life may most easily be studied
in the Freshwater Mussel. In repose this animal lies half
buried, front downwards, in the mud, with the posterior
end, where the "siphons " open, projecting into the over-
lying water, and the valves of the shell slightly gaping.
Currents of water, set agoing by the "cilia" which line
the mantle-chamber and gills, and carrying air and the
microscopic particles on which the animal lives, pass into
the mantle-chamber at the incurrent siphon and sweeping
the gills, where they exchange their oxygen for carbonic
acid, reach the mouth, where they deliver up their burden
of nutriment. Ultimately they pass out at the excurrent
siphon sweeping the vent as they go.

The marine Bivalves live either buried in the mud or
firmly attached to rocks, etc : many, however, are able to
crawl or hop by means of their muscular foot, and some swim
with some activity by opening and closing the valves of
the shell, like wings. The group of Pholads and Teredos
live deeply buried in rock, submerged wood, etc., which
they excavate by rotating their often specially hardened
shells. The Razor-shells burrow deep in the sand.

Many Bivalves are able to form pearls, which are only
derivations of the iridescent pearly layer (" mother-of-
pearl,'' or nacre) that lines the shells not only of Bivalves

140 A Guide to the Zoological Collections in the

but also of many Gastropods, etc. The pearl is formed by
the deposition of successive layers of nacre round small
foreign bodies that have found their way beneath the mantle.

We may follow Professor Ray Lankester in dividing
the Lipocephala into three Orders, namely, (i) the
Isoinya [e.g., the Freshwater Mussel) in which the anterior
and posterior adductors are of much the same size; (2) the
Heteromya {e.g., the true Mussel of seas and estuaries)
in which the anterior adductor is much smaller than the
posterior ; and (3) the Monomya {e.g., the Oyster) in which
only one muscle — the posterior adductor — is present.

i. LIPOCEPHALA ISOMYA.

mszQ X72JI-X77C].
This large Order is divided into two sub-Orders, namely,
(i) the Integripallia, in which the siphons, when present,
are small and do not lead to an inflection of the pallial line,
and (2) the Sinupallia in which large siphons are always
present and mark the shell with a " pallial sinus ".

a. ISOMYA INTEGRIPALLIA.

[(Hascs 172^-17415].
This sub-Order includes five family-alliances of marine
and fiuviatile Bivalves.

ist Family Arcacea, [Cases 172 A, B, C].

In this family the edges of the mantle-lobes are not
united below the foot and there are no " siphons ". The
shell, which is usually thick and heavy and covered with a
tough epidermis, is very often ribbed like a cockle shell.
The "hinge-Hne" is very commonly quite straight, and the
" hinge-teeth" are usually subdivided into numerous denti-
cles of nearly equal size, which are arranged in an equidi-
stant series like the teeth of a comb. The great majority
of the species are marine, Nucula, Yoldia, and Limopsis

Invertebrate Gallery of the Indian Museum. 141

occur in beds in the mud of the Bay of Bengal at depths
of two to five hundred fathoms.

2nd Family Trigoniacea, [Case 172C].

This is a geologically ancient but now small and almost
extinct Family, Both the animals and the shells much re-
semble Cockles. The edges of the mantle-lobes are not
united, and there are no siphons. The interior of the
shell is remarkable for its magnificent pearly lustre. The
hinge-teeth are few and large. One of the finest species
of the whole family is Verticordia eburnea dredged in the
Andaman Sea at a depth of 188 — 220 fathoms, and described
and figured in the Annals and Magazine of Natural His-
tory for December 189!. A perfect specimen of this
beautiful species is exhibited in Case i j2C. By some
mischance a duplicate of this species found its way in 1893
into the London market and has been redescribed under
the name of Verticordia optima.

3rd Family Unionacea, [Case 173 A, B].

This large but uniform family includes the various
Freshwater Mussels, which are found in rivers lakes and
ponds in every part of the world. The lobes of the mantle
are not united below, but their fringed and bilobed pos-
terior edges — as may be noticed in the several dissections
of Unio above Case 173 — do cohere slightly below the level
of the vent so as to mark off two distinct channels, — an
incurrent and an excurrent,. The shell is covered on the
outside with a thick dark epidermis, and on the inside is
almost as lustrous as the Pearl-Oyster. Freshwater Mus-
sels, in fact, not unseldom secrete very good pearls.

4th Family Luclnacea, [Case 173 B,C].

In this not very large but very widely distributed family
the shell, typically, is stout and almost circular in outline.
The condition of the mantle-lobes varies : sometimes
{Astarte) they are separate throughout ; sometimes

142 A^Guide to the Zoological Collections in the

[Galeomma) they are united in front and prolonged behind
into two siphons ; and in other cases {Lucina) they are in
an intermediate condition, being separate in front and
united behind, somewhat as in the Freshwater Mussels, to
form siphonal pockets. In Kellia the mantle-lobes meet
and are produced in front^ to form a respiratory tube.
The Lucinacea are marine.

5th Family Cyprinacea, [Cases 174 A, B].

This family includes the Clams and Cockles. The con-
dition of the mantle here also varies : in all cases the lobes
are united behind to form distinct but short siphons, the
free edges of which are usually fringed with tentacles ; but
whereas in the Cockles they are separate in front, in the
Clams they are united, thus closing the mantle-cavity.
The Cockles are of universal distribution and occur both in
the sea and in freshwater: the Clams are entirely tropical
and marine. The Cockles are freely locomotive, using
their curved foot for leaping : the Clams, on the other hand,
are fixed, either being attached by a strong byssus, like
the Tridacnas, and deeply wedged into growing coral-rock;
or, as the Oyster-like Chamas, being firmly adherent to
the rock by the surface of one valve.

Some species of Tridacna reach an enormous size : a
specimen nearly four feet long, and more than two men's
load in weight, is placed below Case 174.

/3- ISOMYA SINUPALLIA.

[cias.c0 i74(!r-i77ar].

This sub-Order includes three family-alliances of chiefly
marine Bivalves.

ist Family Veneracea, [Cases 174C— 176B].

In this family, which is one of the largest of the whole
Class, the lobes of the mantle, though widely open in front"
for the passage of the foot, are united below and behind,
where they are prolonged out to form two tubular siphons

Invertebrate Gallery of the Indian Museum, 143

which are often of great length. The siphons are retrac-
tile, and when retracted are lodged in the deep inflexion
known as the pallial sinus (see the prepared shell of
Hiatula in Case 172A).

The shell is usually thick and solid, but is sometimes
as in the species of Tellina, thin and delicate.

The Veneracea are of world-wide distribution, and the
great majority of the species are marine, although a
few are found in the brackish waters of estuaries. For
the most part they live buried in sand or mud in shallow
water ; but a few species bore into solid rock.

2nd Family Myacea, [Cases 176 B,C — 177A]. '

The typical forms of this family are known as
" Gapers ", from the fact that the valves of the shell gape
even when fully adducted. The lobes of the mantle are
united throughout, except for a small chink in front for
the passage of the foot. The siphons are generally large
and long and are very often bound together along more or
less of their extent and enclosed in a common envelope of
skin. In many cases the gills are prolonged into the in-
current siphon. The hinge-teeth of the valves in this
Family are often ill developed. The Myacea are for the
most part marine, but a few are estuarine and fluviatile.
Their usual mode of life is deeply embedded in sand or
mud with the ends of the siphons protruding from between
the gaping valves of the shell : some species, however, bore
into rock.

3rd Family Pholadacea, [Case 177 B, C].

This family includes the universally distributed Pholads
and Shipworms, that work such damage to piers and
breakwaters, into which, whether wood or stone, they bur-
row in swarms. The long cylindrical burrows in which
the Shipworms live are more or less completely lined with
carbonate of lime, and form shelly protective tubes in which
the true shell lies ; and in Aspergillum the true shell itself
becomes incorporated with the protective tube, the two

144 -^ Collide to the Zoological Collections in the

forming a single structure. This is well seen in the pre-
pared specimens of Aspergillum in Case 177C.

In the Pholads the umbonal reign of the shell is pro-
tected by a large single or paired shelly plate, and some-
times also the base of the siphons is enclosed in a special
shelly cup. The shell in this family, therefore, is always
more or less complicated and unlike the ordinary Bivalve
shell. Notice the great worm-like tubes of Kuphus in
Case 177.

It should further be noticed respecting the Pholad shell
that there are no hinge-teeth, and that the front part of
the valves has a rasp-like surface. It is by its own rota-
tion, with this rasp-like surface foremost, that the animal
bores its way into rock or timber.

The animals themselves are worm-like : the mantle
is closed, except for a small aperture in front for the foot,
the siphons are of great length and are usually united
throughout their whole extent, and the gills are prolonged
into the incurrent siphon.

ii. LIPOCEPHALA HETEROMYA.
[€a0£ 178JI].

This Order includes the Mussels, in which the anterior
adductor muscle of the shell (see the prepared specimen
in Case 172 A) is very much smaller than the posterior, in
consequence of the extreme attenuation of the anterior
part of the shell.

In the typical Mussels {Mytilus-A.x).A Modiold) the lobes
of the mantle are quite separate, and no true siphons
exist; and the foot secretes a " byssus," by which the
animal attaches itself to foreign bodies : the shell is long
and pointed in front, and is covered on the outside with a
thick epidermis, and there are no hinge-teeth.

Lithodomiis does not merely fix itself to the rocks by
its byssus, but actually excavates a narrow burrow in which
it lies concealed.

Invertebrate Gallery of the Indian Museum. 145

The typical Mussels [Myttlidce] are marine and are
found in all parts of the world, living together in vast
beds.

ill. LIPOCEPHALA MONOMYA.
[€as£s 178^—179(1].

This Order includes the Oysters, Scallops, Pearl-
oysters, etc., in which in the adult the anterior adductor
muscle is absent (see the prepared shells of Oyster and
Scallop in Case 172A, and the dissected spirit specimens
of Amussium and Spondyliis above Case 179).

1st Family Aviculacea, [Case 178 B, C].

The lobes of the mantle are separate throughout and
fringed, and there are no siphons or siphonal folds : the
foot is small and secretes a byssus for permanent attach-
ment. The shell is generally covered on the outside with
a thick, fibrous, often vallanced epidermis, which is com-
monly of a dark green or black colour. The internal
"mother-of-pearl" lining, though often of surpassing
lustre, is always limited in extent, sometimes not occupy-
ing as much as a fourth of the whole internal area. Hinge-
teeth are usually absent. The family though small is
widely distributed : it includes many large forms, among
them the famous Pearl-Oyster of the Indo-Pacific.

2nd Family Ostracea, [Cases 179 A, B, C,].

In this family, which includes the Scallops {Pecten),
the Thorny Oysters [Spondylus), and the true Oysters
{Ostrea), the edges of the mantle, which are quite free
throughout, are fringed with tentacles, and are often fur-
nished with a row of highly developed eyes (see the dis-
sected spirit specimens of Amussium and Spondylus
above Case 179). There are no siphons. Hinge-teeth
are usually absent, but are well developed in Spondylus.
The Pectens, though able to secrete a byssus for (tem-
porary) attachment, are able to progress with great activity

146 A Guide to the Zoological Collections.

by the rapid opening and closing of the valves of the shell
in a flying fashion. The young of Spondylus can also move
in the same manner. The Oysters are always, except in
their very earliest stageSj permanently fixed.
The Ostracea are represented in every part of the globe.

The student of Malacology should consult the article
Mollusca by Professor Ray Lankester in the latest edition
(1883) of the Encyclopedia Britannica.

INDEX.

Page

Page

Acanella .

. . 34

Ankyroderma

, . no

Acant hasten 98

99, 100

Annelida

43

Acanthella

. . j6

Anomala . .

. . 75

Acanthephyra .

. 69

Anomura

75

Acanthephyridae

. . 69

Antedon .

. . 104

Acanthocephala

42

Antennularia .

22

Acanthodesmus

. . 88

Anthenea .

. 100

Acanthogorgia .

. 34

Anthenoides .

100

Acarina . .

. . 86

Anthozoa .

. . 23

Achelous . .

71

Antipatharia .

30

Achetidae . .

. . 92

Antipathes

. . 30

Aciculidae . .

121

Ants . . .

. 96

Acmaeidse . .

. . 119

Aplirocallistes

. . 16

Acorn-shells . .

57

Aphrodita . .

46

Acridiidse . .

. . 93

Aplysiidae . .

. . 128

Acrosoma . .

• 83

Apodogaster

no

Actsea , . .

. . 70

Apolemia

. . 21

Actlnacantha .

. 83

Aporrhaidse

122

Actiniaria . .

. . 23

Appendiculata

. . S3

Actinometra

103, 104

Aptera (Hemipt

era) 94

Actumnus

. 70

Apus . . .

. . 56

Agalmopsis . .

. 31

Arachnida . .

81

Agaricia . .

, . 28

Arachnoides .

. . 108

Albunea . .

77

Araneida . .

81

Albuneidae. .

• 77

Arcacea . .

■ . 140

Alcyonacea . .

• 32

Archaster . .

99

Alcyoniomorpha

• 31

Arcturus . .

. . 61

Alcyonium , .

32

Argonaut .

134. 135

Alpheidae . .

. 68

Aristaeopsis ,

. . 67

Alpheus . .

. 68

Aristaeus , .

. 67

Alveolina . .

0

Armadillo . .

. . 60

Alveopora . .

29

Arthropoda

52

Amoeba . .

• 9

Ascaris . .

. . 42

Amphihelia . .

27

Ascetta . . .

13, '5

Amphipoda . .

• 59

Aspergillum .

143. 144

Ampullaridse .

. 121

Assiminea

. . 120

Amussium . i

375 145

Astacidea .

66

Anamath'ia

73

Astarte . .

. . 141

Andania

' 59

Asterias . . .

. 100

Androctonus

. 84

Asterina - -.

. , 100

Anilocra . . .

. 60

Asterodiscus ,

100

Ankylostoma .

42

Asteroidea . ,

. 98

Page

Asthenosoma .

IC4, 108

Astraeidae ,

. . 27

Astroides

^9

Astropecten .

• . 99

Astrophytidae .

lOI

Astropsammia

. . 29

Astropyga .

108

Astroschema .

. . 102

Atergatis . .

70

Athanas . .

. . 68

Atlantacea . .

126

Atmetochilus

. S3

Atolla . . .

. 36

Augur Shells .

. 123

Aulochone .

16

Aulospongus .

. 16

Auriculidae . .

. 129

Aviculacea . .

. 145

Azygobranchia .

• 115

Balanophyliia

29

Barnacles . . .

57

Basommatophora .

129

Bathyactis . . 28

29

Bathynomus . .

60

Bathypathes . ,

30

Bees ....

96

Beetles ....

95

Benthodytes . .

no

Beroe ... 36,

37

Bird's-nest Sponge .

16

Birgus . . jy

78

Bivalves

'35

Blattidffi ....

92

Boat-shells . . .

125

Bohadschia . . ,

110

K 2

148

Index.

Page

Page

Book-scorpions

85

Cassis . . .

122

Bopyrus . . .

. 60

Catometopa .

. . 71

Bougainvillea . .

20

Caudina . .

108, no

Brachiopoda .

49

Caulospongia .

. . 17

Brachyura . .

69

Cavernularia .

33

Branchiomma

47

Cellepora

. . 52

Brisinga . . gS

100

Ceilularia . .

52

Brissopsis

. loS

Cenobita .

. 76,78

Brissus ....

loS

Cenobitidae

. 78

Brittle-Stars . .

100

Centipedes

. . 87

Bubble-shells . 127

128

Cephalopoda .

. 130

Buccinidae . .

124

Ceratoisis

. . 34

Buccinum .

124

Ceratonota

. 128

Bugs ....

94

Cera±othoa

. . 60

Bulla . .

12S

Cerianthus

. 24, 25

Bullidse ....

127

Cerithidae . .

116, 117

Buthus . . . .

84

Cerithidea

117

Butterflies . . .

94

Cerithiutn

. . 117

Cestoda . .

39

Cestum

. . 37

Chsetaster . .

100

Chaetognatha

. . 42

Chaetopoda

44

Chsetopterus

. . 47

Chalina

. 14, 17

Chalinissa

. . 17

Cacospongia . .

'7

Chalinopsilla .

17

Cadulus . .

<3o

Chama. .

• . 142

Cjecidae . . .

iiS

Chelifer

. 85

Calappa . , .

74

Chilomonas .

. 10

Calappidae . .

74

Chilopoda . .

87

Calcareous Sponges

15

Chitons

. . 114

Calcispongise . .

15

Chloeia , .

• 45. 46

Callianassa

65

Chloridella

. . 62

Callianassidae

65

Chlorodius . .

70

Callianidea . .

65

Chlorodopsis

. . 70

Caliiaster .

100

Chondrilla

16

Callistephanus ,

34

Chondrospongiae

. 16

Calypterinus .

34

Chorinus

73

Cancellaridae .

124

Cicada . .

. . 94

Cancridae . .

• 70

Cidaris 104, 106,

107, loS

Caprella

59

Cidaroida

. . 106

Capulidae

. 120

Cirratulus

. 46

Cardisoma . .

71

Cirrhipathes .

. . 30

Caridea . .

67

Cirripedia . .

51

Carinacea . .

126

Cladocora

. . 27

Carmarina

. 20

Clams , . .

142

Carpilius . .

70

Clathria

• . '7

Carrier-shells

. 118

Clathrissa .

«7

Carterispongia

'7

Cleantis

. . 60

Caryophyllia . 2

6,29

Clibanarius .

77

Page

Clypeaster

. . 108

Clypeastroida

106

Cnidaria . .

• 17

Cochineal Insect

94

Cockles . .

138, 142

Cockroach

. 88, 92

Ccelenterata .

. . 12

Ccelomata . .

37

Cceloria

. 27

Ccenopsammia .

29

Ccerostris . .

. 83

Coleoptera

95

Colobocentrotus

. loS

Colochirus . .

110

Colossendeis .

. . 81

Comatulidse

. 103

Conchoderma

. 58

Cones

. 123

Conidse . .

. 123

Copepoda

. 56

Cordylophora

. 22

Cornacuspongiae

. . 16

Corydendrium

18, 22

Coscinaraea

28

Cowries

. 123

Crabs . .

. 69

Crane-flies

. 94

Crangon

68

Crangonidae .

. 68

Crania

50

Craspidaster

. 99

Crayfish

. 67

Crepidula . .

. 120

Crickets.

92

Crinoidea

. 102

Crotalocaris

. 67

Crucibulum

. 120

Crustacea

55

Cryptobacia

. 28

Cryptodromia

75

Ctenidiobranchia

, 127

Ctenocella

34

Ctenophora

• 36

Cucumaria

no

Culcita . ,

. 100

Cuma . .

. 124

Cumacea

. 61

Cup and Saucer

Limpets . .

120

Cuttlefish, 132,

133, 134

Cyathohelia . .

27

Cyclograpsus

• 72

Index.

Cyclometopa

Cycloporus

Cyclops

Cyclosa

Cycloseris

Cyclostomidae

Cydippe

Cylicia

Cyllobelus

Cymo

Cymothoa

Cyprseidae

Cyprinacea

Cyriopagopus

Cysticercus

Cytaea . .

Page

70
. 38

57
. 83

28
. 121
36,37
. 27

83
. 71

60

. 123

142

• 83

40,41

. S3

Decapoda (Cephalo-
poda) . . . .135
Decapoda (Crustacea) 62
Deima . . loS, 109, no
Deltocyathus
Dendrilla
Dendrophyllia
Dentalium
Diadema
Diadematoida
Diaseris
Diastylis
Dibranchiata
Dictyocylindru
Diogfenes .
Dipsacaster
Diptera.
Discotrochus
Distoma .
Doclea ,
DolidjE
Dolium .
Dorippe
Dorippidse .
Dorocidaris
Dorodotes
Dragonflies

26

. 17

. 29

130

. 108

106

. 28

61

. 134

16

• 77

100

89,94

26

. 39

73

. 12?

122

• 75
74

05, loS
68
93

Dromia

Dromidae

Dytaster

Page
75

Ear- shells

Earthworm

Earwigs

Ecardines .

Echinaster

Echinodermata

Echinodictyum

Echinodiscus 106,

Echinoidea

Echinolampas

Echinometra

Echinonema

Echinoplax

Echinopora

Echinorhynchus

Echinostrephus

Echinothrix

Egeria . .

Encephaloides

Entalis .

Entomostraca

Eozoon .

Epeira

Ephemeridae •

Ephyrina

Epixanthus

Epizoanthus .

Erichthus

Eriphia

Errantia

Eryontidae

Esperella

Ethusa

Etisus . .

Eucopia

Eudendrium

Eudora

Eunice . 43, 44, 45

Eunicella

Euphronides

Euphyllia .

115
44,47
92

50
100

07

17

loS

104

loS

108

17

73

27

42

loS

loS

73

73

130

55,56

10

82,83

93

. 69

70

24. 25
62

• 71
46

. 66
'7

. 75
70

. 62

18, 22

• 70
46,47

• 34
110

. 27

Euplectella

Eupompe

Eupsammii

Eupsammidae

Eupyrgus

Eurythoe

Euxanthus

'49

Page
15, 16
. 46
29
. 29

no
. 46

70

False Limpets

,

119

Farrea .

16

Faunus , . .

,

118

Favia . . .

" 27

Favositipora , .

29

Feather-stars .

102

Fibularia . . .

108

Fig-shells . .

122

Filaria . . ,

,

42

Fish-insect

91

Fissurellidse . .

.

n5

Flabellum . .

26

, 29

Fleas ....

94

Flies . . .

94

Flukes , . .

38

39

Foraminifera

8

Forficulidae

.

92

Freshwater Mussel

137

I

39.

141

Freshwater Prawns

07

68

Freshwater Shrimps

69

Freyella . . .

,

100

Frog-crabs .

75

Fromia . . .

100

Fungia . . .

28

Fungida . .

.

28

Fungldae . .

28

150

Index.

Page

Page

Page

Gadflies

. 94

Homolampas

. 108

Gagrella . .

. 84

Homolidse .

75

Galacantha . .

. 79

Homoptera .

. 94

Galathea . .

79

Hoplophorus

. 69

Galatheida

. 78

Hsemodipsa . .

. 48

Hormosina

9

Galatheidae . .

• 79

Haliglossa •

28

Horny Flinty Sponges 16

Galaxea . • .

. 27

Haliotidse . .

• "5

Horny Sponges

. 16

Galeodes . . .

85, 86

Haliporus . .

67

Huenia . . .

• 73

Galeomma . .

. 142

Halisceptrum

. 33

Hyalinoecia .

46, 47

Gapers . . .

. "43

Halistemma .

. 21

Hyalonema

16

Gasteracantha .

.82,83

Halme . . .

. 17

Hydnophora .

. 27

Gastropoda . .

. 113

Halomitra

28

Hydra . , .

. I 22

Gebia . . .

65

Haplochalina

• 17

Hydrobia

. 120

Gebiopsis

• 65

Haplodactylus

110

Hydromedusae

18

Gecarcinidse

71

Haplomorpha

. 128

Hydrozoa

. . 18

Gecarcinus .

. 71

Harelip-shells .

124

Hylaeocarcinus

• 71

Gelasimus . . .

72

Hectocotylus

• 134

Hymenaster .

99, 100

Gennadas.

. 67

Helicidae . .

129

Hymenicus . .

. 72

Gephyrea . .

49

Helicinidae

. 121

Hymenopenseus

. 67

Glass- rope Spong'e

. 16

Heliopora

32

Hymenoptera

• 89,95

Globigerina . .

9

Helmet-shells

. 122

Hyphalaster . .

. 100

Glomeris . . .

. 88

Hemipenaeus .

67

Hypsophrys

• . 75

Glossophora

113

Hemiptera .

89,93

GJyphocrang-on .

. 68

Hermit Crabs

77

Glyphocrangonidse

68

Herpolithal . .

. 28

Gnathophausia .

. 62

Heterocarpus

68

Gnats . . . .

94

Heterocentrotus

04, 108

Godeffroyia . .

. 33

Heterocera •

• 95

GoniastrEea

27

Heterocyathus

26, no

Ibaciis . . .

. .66

Goniocidaris .

. 108

Heteromya . .

. 144

Ichneumon flies

. 96

Goniodiscus

100

Heteropoda (Gast

opoda)

Idotaea . .

. . 60

Goniograpsus

. 72

. 125

Inachidae

. 73

Goniopora .

29

Heteropsammia

. 29

Insects . .

. .88

Goniosoma . .

• 71

Heteroptera' .

. 94

lotrocha . .

17

Gonodactylus . .

62

Heterozius

70

Iphis ....

• 74

Gorgonacea .

. 33

Hexactinellida .

. IS

Isis . . ,

. . 34

Gorgonella

34

Hexapoda .

88

Isometrus . .

. 84

Gorgonia

32,34

Hiatula . . .

. 143

Isomya . . .

. 140

Grantessa . . .

'5

Himantarium .

88

Isopoda . . .

. 59

Grapsidae

. 72

Hippa . . .

76, 77

Ixa ....

. 74

Grapsus . . .

72

Hippasa . .

83

Ixodes . .

. 86

Grasshopper S8,

90, 92

Hippidse . •

. 76

Gregarina . . .

10

Hippolyte . .

68

Gregarinida . .

8

Hippolytidse

. 68

Guineaworm . .

42

Hippospongia .

17

Gymnosomata .

. 131

Hircinia . .
Hirudinea . .
Hirudo . . .

. 17

. 48

. 48

Holochlamyda .

116

Janthina . .

. U7

Holothuria 98, 1

39, no Janthinidse' . .

. 117

Holothuroidea

108 .

[uncella. . .

. 34

Index.

151

Page

Page

Lithactinia , .

. 28

,

Lithadia , . .

• 74

Lithodomus .

. 144

Littorinidae . .

120

Lobsters . .

. 66

Lobularia . . .

. 32

Kellia 142

Keyhole Limpets . 115
King Crab ... 79
Kuphus ... 144

Locustidae . .
Loligo .
Lophactaea . .
Lophohelia , .
Lophoseridae .

. 92

• 135

. 70

• 27

. 28

Lophoseris .

. 28

Lophozozymus

• 70

Loricata . , .

. 05

Lovenia . . 107, loS

Lucernaria. .

35, 36

Lucina . .

. 142

Lac insect

. . . 94

Lucinacea . • .

. 141

Laetmogone

. . no

Luidia. .

• 99

Lagan um .

. . 108

Lycosa ....

82, 83

Lambrus

. . 73

Lyreidus . . .

• 75

Lamellibranch

la . . 135

Lysiosquilla . .

. 62

Leaf insect .

. . 92

Leech . .

. . . 48

Lepas

. . 58

Lepidoptera

. • 89,94

Leptastrsea .

. . 27

Leptoctenus

. . . 83

Leptodius

. . 70

Leptogorgia

. . . 34

Macrocheira .

• 73

Leptoptilum .

• . 33

Macrophthalmus

• 72

Leptoseris .

. . 28

Madreporaria

• 25

Leptostraca .

• . 79

Madreporidae

. 29

Leucandra

• . >5

Maeandrina

. 27

Leucosia . .

. • 74

Magilus .

. 125

Leucosidae

• • 74

Maiidae

. 73

Libellulidae .

• . 93

Malacostraca

. 58

Lice . .

• • 94

Mantidae . .

. 92

Ligia . . .

. . 60

Maracandus .

. 84

Limacidae .

. 129

Maretia . . .

. 108

Limnaeidae

. . 129

Marginella . .

• 125

Limnaeus .

. . 129

Marisa ....

. 114

Limnatis .

. . 48

Marsenidae . .

119

Limopsis .

. . 140

Marsipaster . .

. 100

-limpet III, II

2, 113.

Matuta . . .

• 74

II.

Limulus .

5, 119, 120
79, 80

Matutidae . . .
Mayflies . . .

• 74
• 93

Linckia

. . 100

MecistocephaluS .

. 88

Lingula . .

. . 50

Mediaster . . .

100

Liocheles . .

. . 84

Medusae . .

, 19

Lipocephaia ,

• ■ 135

Mcgalopa . . .

39

Page
Melanidae . . . .117
Melithaea. ... 34
Melon-shells . . .125
Menippe .... 70
Mertensia . • . . 37
Merulina .... 27
Mespilia ; . . 108

Meta 83

Metacrinus. 102, 103, 104
Metalia .... 108
Metapenzeus ... 67
Metasesarma . . 72
Metazoa .... 10
Micippa .... 73
Millepora . . .18, 21
Millipedes . . ^j, 88
Milteliphaster . , 100

Mites 86

Mithrax .... 73
Mitrids .... 125
Modiola . . , .144
MoHusca . . . . Ill
Monera .... 9
Monomya . . . 145
Montipora ... 29
Montlivaltia ... 27
Mopsea .... 34
Mosquito ... 94

Moths 95

Mulleria . . (09, iio

Munida 79

Munidopsis ... 79

Murex 124

Muricea .... 34
Muricidae . . . .124
Muisia .... 74

Mussa 27

Mussel . . . 139, 144
Myacea .... 143
Mygale ... 82, 83

Myra 74

Myriapoda ... 87
Myrodes . ... 74
Mysis stage . . 61, 79
MytiUdae . . 144, 145
Mytilus . . . .144

152

Index.

Page

Page

Page

Oncidiidae .

129

Paludinidce , .

. 120

Ophiarthrum

. lOI

Palystes . .

. . 83

Ophidiaster.

100

Pandalidae . .

. 68

Nardoa . . •

, 100

Ophiernus

. lOI

Pandalus .

. . 68

Nassa . .

. 124

Ophiocamax

lOl

Pandinus. .

. 84

Naticidse . . .

. 119

Ophiocnemis .

. loi

Pannychia . .

. . no

Navicella

. 117

Ophiocnida

101

Panopeus . .

• 70

Nebalia . . .

56, 79

Ophiocoma .

. loi

Paper Nautilus

. 135

Nemathelminthes

. 41

Ophioglypha . .

. lOI

Papillina . .

16

Netnatocarcinidse

. 69

Ophiolepis . .

Id

Paracyathus .

, . 26

Nematocarcinus .

. 69

Ophiomastix .

. lOI

Paradesmus

. 88

Nematoda . .

. 42

Ophiomussium

101

Paragonaster .

. . 100

Nemertina

. 41

Ophiophragmus

. lOI

Paramoecium

10

Nephila . . .

. 83

Ophiothrix .

100, 1 01

Paramuricea .

. • 34

Nephilengys

. S3

Ophiozona

. 101

Parapaguridae .

. 77

Nephrops .

. 66

Ophiuridse .

. 101

Parapagurus .

• . 77

Nephropsidse

. 66

Ophiuroidea . .

. 100

Parapasiphae

. 69

Nephropsis . .

. 66

Opisthobranchiai

126, 127

Pararchaster .

. 100

Neptunus

. 71

Orbitolites . .

. 9

Paratelphusa

. 71

Nereis . . . .

• 45

Oreophorus . .

. 74

Parilia » . .

. . 74

Neritella . . .

• 117

Organpipe Coral

31.

Paromalopsis

• 75

Neritidse . .

116, 117

32, 33

Parthenope .

. . 73

Nerocila . . .

. 60

Orphnaeus .

. 88

Parthenopidae .

. 73

Neuroptera . .

. 93

Orphnurgus .

. no

Pasiphae .

. . 69

Non-palliata. .

. 128

Orthoptera . .

. 91

Pasiphaidae . .

. 69

Notopus . . .

• 75

Ostracea . .

• 145

Patellid^ . .

. . n5

Nucula

1 38, 140

Ostracoda .

. 56

Pavonia . .

. 28

Nudibranchiata

. 128

Ostrasa . . .

. . 145

Pearl Oyster .

• . 145

Nummulina

. . 9

Otostigma . .

. 88

Pearls . .

139, 140

Nursia . . .

. 74

Oxypleurodon

. . 73

Pearly Nautilus

134

Nymphaster

lOO

Oxyrhyncha'. .

■ 72

Pecten

. . 145

Oxystoma .

. . 73

Pectinura . ,

loi

Oyster . 137,

'39, 145

Pedicellaster
Pedicularia .
Pedicularidse .
Pedipalpi . .
Pelagonemertes
Pelecypoda .
Penaeidae

loo

. . 123
. 123

. . 85

41

- . 135

. 67

Ocnus . . ,

. no

Penaeus . . .

64,67

Octopoda . .

. 135

Pagundas . .

. . 77

Pennatula . .

33

Octopus .

■ 135

Paguridea .

• 77

Pennatulacea .

. . 33

Oculinidse . .

. . 27

Pagurodes . .

. . 77

Pentaceros

. . 100

Ocyale . .

. S3

Pagurus . .

. n

Pentacheles

. 66

Ocypoda

. . 72

Palaemon

. . 69

Pentacrinidae .

. . 102

Ocypodidae . .

. 72

Palsemonidje .

. 69

Pentacrinus .

. . '04

Oligochseta

. . 47

Palamnseus .

. 84

Pentagonaster

. . 100

Olindias . 19, 2

3, 22, 36

Palinuridae

. 66

Pentastomida .

. 86

Olive-shells .

. 125

Palinurus

. . 66

Pentastomutn .

86

Olividae .

. 125

Palliata . .

. 127

Perigonimus .

. 18, 20

Onchidium , .

. . 129

Palmipes . .

. 100

Peripatidea.

68

Index.

153

Page

Page

Page

Peripatus . .

86, 87

Polycyathus . .

. 26

Periwinkles . .

120

Polyplacophora

114

Peronella . . .

. 108

Polysiphonia . .

24. 25

Persephonaster

100

Polyzoa . . .

51

Petrolisthes . .
Phakellia . . .

• 79
16

Pond Snails .
Pontaster . .

. 121

100

yuadrella . .

71

Phalangiida . .

. 83

Pontobdella . .

. 48

Phalangium . .

84

Pontonia . . .

. 69

Phasmidse . .

. 92

Pontoniidae . .

. 69

Pheronema . •

14, 16

Porcellana . ,

79

Philyra . . .

. 74

Porcellanaster

. 100

Pholadacea . .

143

Porcellanida; .

79

Pholads i39j "43, '44

Porifera . . •

12

Randallia .

• 74

Pholcus .

82, S3

Porites . . .

29

Ranina . . .

. 75

Phormosoma . 104,

Poritidse .

. 29

Raninidae . .

• 75

107, loS

Porocidaris .

loS

Raninoides , .

• 75

Phrynus . . .

85

Portunidae . .

. 71

Rapana . .

. 124

Phyllacanthus

. loS

Poterion . .

16

Raphyrus .

. 16

Phyllopoda . .

56

Prawn ....

• 55

Raspailia

16

Phyllosoma . .

. 79

Prionastr^ea

27

Razor-shellb . .

. 13S

Phyllospongia . .

'7

Prionechinus .

. loS

Remipes . .

. 76

Phymastraea , .

. 27

Protosquilla

62

Reniera . .

14, 17

Physalia . . .

21

Protozoa . . .

. 7

Retepora . .

5". 51

Physophora .

. 21

Psalidopodidse

6S

Rhabdosoma.

. . 59

Pilumnus . ,

70

Psalidopus . .

. 68

Rhiphidigorgia

. 34

Pinnotheridae

. 72

Psammocara

28

Rhizostome;e

• . 35

Plagusia . .

72

Psathyrocaris

. 69

Rhizotrochas

26, 29

Planaria . . .

. 38

Pseudarchaster

100

Rhodopsammia

. 29

Planorbis . .

129

Pseudoneuroptera

. 93

Rhopalocera

• 94

Planorbulina . .

• 9

Pseudoscorpionidea 85

Ricinula

. . 124

Plant lice . .

94

Pseudosquilla

. 62

River-snails

. 120

Platyhelminthes .

. 38

Pseudozius . .

70

River-worms .

• . 47

Platymaia . .

73

Psychropotes

. no

Rostellaria .

. 122

Plesiastrsea . .

. 27

Pteroceras . .

122

Rotella . .

. . 114

Plesiofungidae .

28

Pteroeides . .

. 33

Rotifera . . ,

• 47

Pleurobranchidae

. 128

Pterogorgia

34

Pleurotomaridae

. 117

Pteropoda . .

. 131

Pleurotomidze

. 124

Pterotracheacea

. 126

Plexippus . .

. S3

Pugettia . . .

. 73

Plumohalichondria

. 17

Pulmonata .

. 128

Plumularia.

iS, 22

Pulvinulina .

9

Pneumochlamyda

121,129

Purpura . . .

. 124

Pocillopora

27

Pycnogonida .

80

Pocilloporidae

. 27

Pycnogonum

So, Si

Sacculina

57, 5S

Podaxonia .

49

Pygobranchia .

128

Sagitta . .

. . 42

Podobacia

, 2S

Pyloclieles

. 77

Salmacis 105,

!o6, loS

Podophthalniidae

71

Pyramidellida; .

. 118

Salticus , .

82, 83

Podophthalmus .

• 71

Pyrazus • . .

. 117

Saltigradai

. . S3

Poecilopoda

79

Sawflies . .

. 96

Polychaeta . .

• 45

Scalaria

. . 117

Polycheles . .

66

Scalaridac

- 117
L

154

Index.

Scallop . .

Scalpellum

Scaphopoda

Schizopoda

Scirpearella

Sclerogorgia

Scolopendra

Scorpion .

Scorpionidea ,

Scorpion-shells

Scorpion-spiders

Scorpiops . .

Screw-shells

Scurria

Scutigera

Scylla

Scyllaridse

Scyllaridea

Scyllarus .

Scyphomedusse

Scytalium

Sea-anemones

Sea-butterflies

Sea-cucumbers

Sea-eggs .

Sea-fans

Sea-feathers

Sea-hares

Sea-lilies .

Sea-mats

Sea-pens .

Sea-rods

Sea-spider

Sea-urchins

Semperella

Sepia ,

Sergestes

Sergestidae

Seriatopora

Serpula .

Sertularia .

Sesarma

Shipworms.

Shrimps , .

Siderastraea

Sigaretus . ,

Siliquaria

Siphonochlamyda

Siphonophora

Siphonopoda

Sipunculus

Page

. 145

.57,58

. 130

. 62

. 34

. 34

87,88

. 84

. 84

. 122

. S5

. . 84

. . 118

. 82, 83

. . 88

64j 70, 71

. . 65

65
. 6G

34
. 33

23

. 131

108

. 104

33

. 33

1 28

, 102

33
. 33

33

80
104

16

33, 134, 135

. 67

67
. 27

• 47

20, 22
. 72

. 143
67, 68

. 28
. 119

. 113

131

49

Page

Page

Slugs . . .

128, 129

Synapta

loS, no

Snails iii, 112,

1 28, 129

Synargea . .

. 29

Soldier-crabs

. 77

Syncoryne

. , 20

Solenocaulon

. 34

Solenocera . .

. 67

Solifugae . .

. 85

Spadella . .

. 42

Spatangoida .

. 107

Sphseropseus

. 88

Sphserozoum

. 10

Sphedanus

. 83

Sphenopus

. 24,25

Tsenia . .

• 39, 4^

Spider-crabs

. 73

Tapeworm . .

39

Spiders . . .

. 81

Tectibranchia

. . 127

Spirobolus

. 88

Tegenaria

82,83

Spirographis

. 46

Telescopium

. . n7

Spirostreptus

. 88

Telesto . . .

31,32

Spirula . . ,

. 135

Tellina

. . 143

Spondylus . .

145, 146

Telphusa . .

71

Spongilla . ,

. 16

Telphusid?e

. . 71

Spongodes

32

Temnopleurus .

loS

Spoonworms

• 49

Terebratula .

. . 51

Squids

. 135

Terebridae . .

. 123

Squilla . . .

61, 62

Teredo . .

• . 139

Stalked Crinoids

. 102

Termes . .

. 92

Stanneoclavis

. 83

Termitidse

. . 92

Starfishes . .

. gS

Testicardines .

. 50

Stellaster . ,

. 99

Tethya . .

. . 16

Stellospongia

. 17

Tetrabranchiata

. 134

Stenella . . .

. 34

Tetragnatha

. . S3

Stenopus . .

. 67

Tetrastemma

41

Stephanotrochus

. 26

Thalamita . ,

. 7t

Stichopus . .

109, no

Thalassicolla ,

9

Stick-insects

. 92

Thalassina

. . 65

Stomapoda

. 61

Thalassinidse

' 65

Stomatia . .

. 117

Thalassinidea

. 65

Stomopneustes

. loS

Thalassodendron

17

Stony-corals

. 25

Thecosomata

. 131

Strepsiptera

. 93

Thelictopis

. S3

Strombida; . .

. 122

Thelyphonus

. S5

Strombus . .

. 122

Thenus . „ .

. 66

Strophogorgia

. 34

Thomisus . .

. 83

Stylocalyx

. 16

Thorny Oysters

• 145

Stylommatophora

. 129

Thouareila

. 34

Stylops . .

. 93

Threadworms

42

Styracaster . .

. 100

Thyone . 97,

loS, no

Suberites

16

Thyonidium

, no

Sycandra . i3, 14. '5 |

Thysariura

. 91

Sycon . . .

13, 15

Ticks

. 86

Syconidre . . .

. 13

Tooth-shells

. 130

Symphyllia . .

. 27

Tornatella

. 12S

Index. .

155

Page

Page

Page

Tornatellidse

. 127

Unio . . .

. 141

Wing-shells

122

Toxopneustes .

. loS

Unionacea . .

. 141

Wood-lice

. . 59

Trachyphyllia .

. 27

Trapdoor Spiders

. 82

Trapezia . . .

. 71

Trapeziidae

. 71

Trematoda

38, 39

Trichocephalus

. 42

Tridacna

69, 142

Tridacophyllia .

. 27

Trigoniacea . .

. 141

Valvatidae . .

121

Xanthasia . .

72

Tripneustes

. 108

Varuna . , .

. 72

Xantho . .

0 . 70

Tritonidse

. 132

Veneracea . .

. 142

Xenophoridae .

. iiS

Trochidee

. 116

Veretillum , .

. 33

Trochoseris

. 28

Vermetidae

. 118

Trochostoma •

. no

Vermetus . >

. 113

Trochus . . •

. 120

Verruca , .

. 58

Trombidium

. 86

Verticordia . .

. 141

Trumpet-shells

. 122

Verucella . .

34

Tuba . . .

. 17

Violet Snails

. 117

Tubicola . . .

. 46

Virgularia . .

33

Tubipora . 31

, 32, 33

Volutidffi . . .

. 125

Yoldia . .

• . 140

Tubularia . 18

, 20, 22

Tun-shells . .

122

Turbellaria . .

. 38

Turbinaria ,

29

Turbinolidae , .

. 26

Turritella . .

. 114

Turritellidae . .

. 118

Zephronia . .

ss

Waldheimia . .

50

Zosea . .

. . 79

Wasp . . .

88,96

Zoanthus . .

24

Wheel-animalcules

47

Zoophyte

. . 12

Whelk . . .

. 124

Zoroaster

100

Umbellula

33

White Ants . ,

92

Zozymus . .

. . 70

Umbrella-shells ,

. 12S

Willemoesia

. 66

Zygobranchia .

. IJ5

G. I. C. P. O,— No. 17 I. M.— 37-6'94.— Soo>

QL362.7 .152 1894

(-.null U. IIk /onlnUK.ll .oikdi.

Harvard MCZ Library M'HS.f

3 2044 062 423 884

]^

j=,rq-

0 B U sT A C E

•5

D

spo N G e: s

M

o

L

L

E
U

C X

s

s
c

A

ia« 127

128 129

130 ,31

m 133

111 I7-.

13.

179

178

177 176

175

174

173 1,2

171

170

169 168

M O L L_ U

I 135

133 122 12i

U4 113

N S E C

D

16

1=

H

13

D N Y C 0 I

FISHES

n

So.lo 1 inohto 10 ft,!,

t^3=C

-,__J-

-prrq-

STONY CORALS

M O

L

^

E

C
U

s

c

A

1« H5

Hf, H7

1«

,50 ,5,

'" '"

,»

.66

16=

,62

,61 ,60

"• 'M

157 ,«

U S C A

103 102 10,

e c -r

STDNV CORAL

T— ^^

GROUND-PLAIN OF THE INVERTEBRATE GALLERY OF THE INDIAN MUSEUM

D

D

g I

nh br SCMonJiJ

/