dictionary, we find that _cyclostomous_ means having a circular mouth.
This species is sometimes called _Turbo elegans_; the beautifully-marked
shells are often found in chalk-hills covered with brushwood. This
pretty mollusk has a curious mode of travelling; the under surface of
the foot, which is long, is divided by a deep fissure, into two narrow
strips, like ribbons; these take hold of whatever the creature may be
moving on alternately; one keeping fast hold while the other advances,
in like manner to fix itself, and drag the body forward. Fig. 6, the
Undulated Plekocheilos, (_P. undulatus_;) the Latin _plecto_—to twist or
twine, seems to be the root from which the generic name of this Snail
is derived; the specific name will be easily understood; to undulate,
is to flow like waves, and the lines on the shell it will be seen are
undulating. This is not a British species, but is introduced here to
give variety to the group; it is a West Indian Mollusk, and is found in
immense numbers in the forests of St. Vincent; it glues its eggs to the
leaves of a plant which holds water, and thus secures for them a damp
atmosphere at all times. And here we must conclude our chapter of Land
Snails, leaving unnoticed very many beautiful and interesting species,
both British and Foreign.
Many poets have alluded to the Snail, but we can only find room for a few
verses by Cowper:—
To grass, or leaf, or fruit, or wall,
The snail sticks close, nor fears to fall,
As if he grew there, house and all
Together.
Within that house secure he hides,
When danger imminent betides
Of storm, or other harm besides,
Of weather.
Give but his horns the slightest touch,
His self-collecting power is such,
He shrinks into his house with much
Displeasure.
Where’er he dwells, he dwells alone,
Except himself has chattels none,
Well satisfied to be his own
Whole treasure.
Thus hermit-like, his life he leads,
Nor partner of his banquet needs,
And if he meets one only feeds
The faster.
Who seeks him must be worse than blind,
(He and his house are so combin’d,)
If, finding it, he fails to find
Its master.
FRESH-WATER SHELLS.
Many of the following group of Fresh-water Shells, are remarkable for
elegance of form, and some for richness of colouring; hence, perhaps,
the scientific name applied to the family in which they are mostly
included—_Limnæidæ_, which, like _limn_—to paint, agrees with the French
_enluminer_. These mollusks are found in rivers, streams, ditches, and
moist marshy places. Like those which live wholly on land, they breathe
through lungs, and therefore cannot exist without air; which accounts for
their frequently coming to the surface, when under water. In brooks, as
well as in stagnant pools, which abound with aquatic plants, they may be
found in vast numbers, feeding upon the moist vegetation.
[Illustration]
The Common Limnea, (_L. stagnalis_,) is mostly an inhabitant of stagnant
waters, where it is often seen floating with the shell reversed, as in
a boat; this shell, like most of those of the Fresh-water Mollusks,
is thin, and easily broken; the shape it will be seen, is peculiarly
elegant, the spire being slender and pointed—very different from that
of the Spreading Limnea, called by naturalists, _L. auricularia_,
from _aurus_—the ear, to which the broad aperture, or opening of the
shell, may be compared; this resembles the other species in its habits.
The Horny Planorbis, in Latin _P. corneus_, from _cornu_—a horn. The
shape, you will see, is flat, the whorls rolling upon each other like
the folds of a bugle horn; this shape would be termed orbicular, from
_orbis_—a sphere, or circular body. This is the largest European species
of Fresh-water Shells so constructed; it is often found in deep clear
ditches, and yields a beautiful purple dye, which, however, soon becomes
dull, and changes; it cannot be fixed, and is therefore valueless. The
mouth of this shell in fine specimens, is tinged with pale violet or
lilac.
[Illustration]
There is another kind, the Keeled Planorbis, (_P. lurinatus_,) which
has the outer edge of the shell finely ridged, or keeled; it is very
small, and very plentiful in fresh-water, both running and stagnant;
where, too, is found the Common Physa, (_P. fontinalis_,) the latter word
meaning a spring or fountain. This little mollusk is a quick and active
traveller, it sometimes comes out of its shell, and throws itself about
in an extraordinary way, keeping fast hold by its foot; the generic name,
_Physa_, would seem to have reference to the round, smooth, delicate
shell, and to come from the same root as _Physalite_, which means a
topaz: the members of this genus are very numerous, being found nearly
all over the globe. The next belongs to the family _Auriculadæ_, or Ear
Shells. The Midas’ Ear, (_A. Midæ_;) this handsome shell is prized by
collectors; it comes from the East Indies. Midas, it is said, was one who
set himself up for a judge of music in the old fabulous times, and not
appreciating that of Apollo, was rewarded by the angry god with a pair of
ass’s ears.
[Illustration]
The Cone-shaped Melampus, (_M. corniformis_,) also an Ear Shell, is
found in the rivers of the Antilles Islands. It is a pretty shell; the
formation is much the same as that of many of the most highly-prized
varieties of Marine Shells; of these we shall have to speak presently.
_Melampodium_ in Latin, signifies a poisonous plant called Black
Helebore; in the Mythology, _Melampus_ was a great magician, who did all
sorts of wonderful things; but we cannot tell what relation there exists
between either the plant or the magician and this pretty cone shell. To
give variety to this group, we will now throw in a land species called
_Megaspira Ruschenbergiana_, about the origin of whose name we cannot
even hazard a guess; the termination of the generic name, you will see
is _spira_, and a glance at the shell will at once suggest a reason
for this; its long tapering spire consists of twenty-three closely-set
gradually increasing whorls. This is a rare shell, whose inhabitant has
not yet been described by naturalists; several of the marine species
closely resemble it in shape. Much more might be said about the Land and
Fresh-water Shells, but we must here leave them, having a wide field
before us, namely, the Sea or Marine _Testacea_, one of the most common
of which is
[Illustration]
THE WHELK,
A univalve shell inhabited by a gasteropod mollusk, or, we should rather
say, naturally so tenanted, for very frequently it is taken possession of
by the Soldier or Hermit Crab, which having no hard covering to protect
their soft plump bodies, are obliged to take lodgings where they can
get them, and generally prefer the Whelk shell, of which we here give a
figure.
[Illustration]
This is one of the commonest of our Marine Mollusks; it is called by
naturalists _Buccinum undatum_; the first, or generic term, being the
Latin for a trumpet, and the second, or specific name, meaning waved, or,
as we often say, undulated. So we call this the Waved Whelk; fishermen
term it the Conch, or the Buckie, and tell strange stories of its
ravenous appetite and murderous propensities; how, with its spiny tongue,
situated at the end of a long flexible proboscis or trunk, it drills a
hole in the shell of the Oyster, or other testacean, and sucks out the
contents; empty shells, so drilled, are frequently found on the shore,
and often, when the dredge is let down into an oyster bed, it comes up
time after time filled with Whelks, of which such numbers are sometimes
taken, that they are sold to the farmers to be used as manure for the
soil. This mollusk is a favourite article of food with the poorer classes
of our land, but it is hard and indigestible. The shell may frequently
be found in large numbers among the beach stones; it is strong and firm,
from three to four inches long, of a dirty yellowish white. There are
two other Whelks common upon our coasts—the Stone or Dog Whelk, (_B.
lapillus_,) from the Latin _lapis_—a stone, and _B. reticulatum_, so
called because the shell is _reticulated_, or marked with many lines
crossing each other, like net-work; it comes from the Latin _reticulum_—a
net; hence also we have _reticule_—a small work bag, at one time very
much carried by ladies.
ROCK SHELLS,
Are so called on account of their rough and wrinkled forms; they are
nearly allied to the Whelks, to which they bear a close resemblance.
Several species are found on our shores, the most common being the Humble
Murex, (_M. despectus_,) from the Latin _despecto_—to despise; this is
often used by the fishermen for bait. Some of the foreign Rock Shells
are very curious and beautiful; three of them will be found on Plate
II.—Figs. 1, 2, and 3. The Common Thorny Woodcock, (_M. tribulus_,)
from the French for trouble, whence we have also tribulation, which is
sometimes said to be a thorny path. This curious shell is also called
Venus’ Comb. It is found in the Indian Ocean, from whence it is also
brought. Fig. 2, the Woodcock’s Head, (_M. haustellum_,) from the Latin
_haustus_—a draught; the bill of the Woodcock being adapted for sucking.
This term is also applied to insects that live by suction. The shell, it
will be seen, is destitute of spines, but it is ribbed and beautifully
marked. Fig. 3 is worthy of its name—the Royal Murex, (_M. regius_,)
from _regno_—to reign. It is a splendid species, of the rich colouring
of which, art can give but a faint impression. It is brought from the
western coast of Central and South America, where, as well as in the
islands of the South Pacific, many new shells of the genus _Murex_ have
been discovered.
[Illustration]
One shell found on our own coast, often mistaken for a Whelk, is the
Pelican’s-foot Strombus, called in scientific language, _Strombus
pes-pelicanus_, which is but a Latinized form of the English name. This
shell varies greatly in shape in different stages of its growth, and by
an inexperienced conchologist, the young, middle-aged, and old Strombus,
might be taken for distinct species. In the _Strombidæ_ family, so called
we know not why, the same word in Latin meaning a kind of shell-fish,
are some species which have produced pearls. One member of the family
which we sometimes see in collections, is a large and very beautiful
shell; this is the Broad-winged Strombus, (_S. latissimus_,) probably
from _latesco_—to wax or grow broad, or large; _issimus_ being in the
superlative degree, would indicate that this shell was very much so, as
we find it is, sometimes measuring as much as twelve inches across. In
Plate II, is a representation of this handsome shell, greatly reduced
in size, of course: see Fig. 4. We here give a figure, as more curious
than beautiful, of the Scorpion Pteroceras, (_P. scorpius_,) which also
belongs to the _Strombidæ_ family; as does the curious Chinese Spindle,
(_Rostellaria rectirostris_.) The generic name of the first of these
species, comes from the Greek _Ptero_, pronounced _tero_, meaning a
wing, and _cerus_—waxen. Both the generic and specific names of the
second refer to the peculiar conformation of the shell, being derived
from the Latin, and meaning a straight line or beak.
[Illustration: CHINESE SPINDLE.]
On Plate III, will be found the Imbricated Purpurea, (_P. imbricata_,)
Fig. 1, which claims a close alliance with the Whelks. The generic name
has reference to the dye yielded by this, as well as all the shells
of the genus; the specific name comes from the Latin _imbrex_—the
gutter-tile; thus _imbricated_, a term often used in Natural History,
means ridged, like the roof of a house, where the tiles are placed to
overlap each other, so that the rain will run off. The Persian Purpura,
or, as it is called in Latin, _Purpura Persica_, Fig. 2, is another
handsome shell of this family group; its name indicates the place where
it is found. The other species described comes from South America, and
the _P. lapillus_, (the meaning of the specific name has already been
explained,) is common on our shores, being found in great abundance on
the rocks at low waiter. We read in scripture, of Tyrian purple, and
there is every reason to suppose that the rich colour was obtained from
these and other shell-fish.
PERIWINKLE.
[Illustration]
This is the commonest representative which we have of the family
_Turbinidæ_, which comprehends, according to Cuvier, all the species
which have the shell completely and regularly _turbinated_, that is, if
we translate the Latin word into English, twisted. The little Periwinkle,
(here he is,) is by no means a handsome mollusk, but some of his
relatives are very beautiful as we shall presently show. He is called
by naturalists _T. littoreus_, from _littoralis_—belonging to the shore,
and often eaten by boys and girls with great relish; but he is not very
digestible, and sometimes occasions dangerous disorders. The Swedish
peasants believe that when the Periwinkle crawls high upon the rocks, a
storm is brewing from the south; but Linnæus quotes a Norwegian author
to shew that according to popular belief, it foretells the approach of a
land wind with a calm on shore. Man may learn much of elemental changes
from an observation of the movements and habits of all living creatures,
which are instructed by God to provide for their safety and wants, and
often perceive, long before man himself does, the indications of calm
and tempest, rain and drought, etc. But our little _Turbo_, what of him?
will you boil him, and pick out his curled-up form with a pin? or let him
go crawling about the rocks, feeding upon the delicate earlier growth of
marine vegetation? In the former case, you will have to reject the little
kind of horny scale attached to his foot, which forms, when he retires
into his habitation, a closely-fitting door to make all snug.
Several species of this genus are found on our shores; one of those is
the _Turbo rudis_, or Red Turbo, which has a very thick periwinkle-like
shell, about three-quarters of an inch long; the colour is dull red,
fawn, or drab.
Of the foreign _Turbinæ_, sometimes called Turban Shells, we will now
introduce two or three species, which will be found on Plate III. Fig. 3
is the Marbled Turbo, (_T. marmoratus_,) from the Latin _marmor_—marble;
a large handsome shell well known to conchologists, and a native of the
Indian seas. Fig. 4 is the Twisted Turbo, (_T. torquatus_;) this shell,
when deprived of its outer coat or layer, is beautifully _nacreous_, or
if we may so speak, mother-of-pearly. The specimens which have reached
England were brought from King George’s Sound. Fig. 5 is called Cook’s
Turbo, (_T. Cookii_:) this is a handsome South Sea shell, oftentimes
of large size. It has been found in great numbers on the coast of New
Zealand.
On Plate IV, we have placed two very curiously formed and marked shells,
called Wentletraps, also belonging to the family _Turbinidæ_. The
scientific name is _Scalaria_, from the Latin _scala_—a ladder, which the
ribbed shells are supposed to resemble. Of this genus there are about
eighty distinct species known; they are mostly deep-sea shells found in
warm latitudes, although several inhabit the European seas, and one, the
Common False Wentletrap, (_S. communis_,) Fig. 1, may often be picked up
on our own shores. Fig. 2, the Royal Staircase Wentletrap, is a rare and
valuable shell, generally brought from India and China; the scientific
name is _S. pretiosa_, given to it by the French Naturalist Lamarck, on
account of the high price which it fetched, _pretiose_, in Latin, meaning
costly, valuable. As much as £100 have been given for a single specimen
of this shell; and a fine one, especially if it exceed two inches in
length, yet commands a considerable sum, although not nearly so much as
that. A good deal like the False Wentletrap in general outline, is the
Awl-shaped Turritella, found in the African and Indian Seas. This is the
_T. terebra_ of naturalists; the first name referring to the turret shape
common to the genus, and the last being the Latin word for an auger, or
piercer. The Roseate Turritella, (_T. rosea_,) is also sometimes seen in
collections; the beautiful rosy tint of the live shell changes to a dull
red or brown, on the death of the mollusk.
TROCHUS, OR TOP-SHELL.
“Of the shelled Mollusca which the dredge ever and anon brings up,”
says Mr. Gosse, in his delightful volume on the _Aquarium_, or
_Aqua-vivarium_, as the glass tank in which living marine animals
and vegetables are kept, is called, from the Latin _aqua_—water, and
_vivo_—to live, “the _Trochi_ are among the most conspicuous for beauty.
The chief glory of this genus is the richly-painted internal surface of
their shells, in which they are not excelled by any even of the true
margaritiferous or pearly bivalves.”
Of this _Trochidæ_ family, a few of the members must be introduced to
our readers; it is rather a numerous one, consisting of more than one
hundred species, which are scattered nearly all over the world, few
seas being without some of them. They are found at various depths, from
near the surface to forty-five fathoms down, creeping on rocks, sand,
masses of sea-weed, etc. We will first speak of those found on our own
shores, the two commonest, as well as the smallest of which, are the Grey
and the Spotted Trochi, scientifically named _T. cinerarius_ and _T.
maculata_, the translation of the first Latin specific name being ashy
or ash-coloured, and that of the second, spotted. _Trochus_, in the same
language signifies a top, and has reference to the shape of most of these
shells, which are something like a boy’s whip-top.
Children on the coast sometimes call the last-named of the above species
Pepper-and-salt Shells, because in colour they resemble the cloth so
named. The Muddy-red Trochus, (_T. ziziphinus_,) so called, perhaps,
because in colour it resembles the ziziphia, or fruit of the jujube tree,
is also common with us. This shell is about an inch long, of a grey tint
dashed with dark spots, these follow the line of the spiral turnings,
which are very regular, proceeding from the opening below to the apex or
point. Seen on shore, its colours are dull and faint, but beneath the
water, inhabited by a living mollusk, it looks as though made of pearl,
and studded with rubies; the animal, too, is richly coloured, being
yellow with black stripes.—See Plate IV, Fig. 3.
Not so common as the last is another British mollusk of this genus,
called the Granulated Trochus, (_T. granulatus_.) It is the larger, and,
as many think, the more elegant shell of the two, being in colour, a
faint flesh tint or yellowish white, shaded here and there with purple;
the spiral lines which encircle it are composed of small round knobs
which stand out like beads.
There is a singular shell of this genus, called the Carrier Trochus, (_T.
phorus_;) it is generally found loaded with foreign objects, such as
shells, small stones, bits of coral, etc., which it attaches to itself,
and so goes about like a collector of natural curiosities, with his
cabinet on his back.
The Imperial Trochus, (_T. imperialis_,) Fig. 4, whose scientific name
explains itself, is one of the handsomest shells of the genus; it is very
rare, and has hitherto been found only at New Zealand. Let us give our
young readers a specimen of the way in which scientific writers describe
shells; thus, this foreign Trochus, they tell us is “orbicularly conical,
the apex obtuse, the whorls turgidly convex, squamoso radiate at the
margin.” This is quite a simple affair to some descriptions, and simple
in fact it is to one, who, by attentive study, has become familiarized
with the meaning of the terms. To one also who is acquainted with the
Greek and Latin tongues, they will be sufficiently plain, although he
has never seen them applied before, for they are all derived from those
dead languages, as they are called, and so convey their own meaning
to every educated naturalist, no matter of what nation he may be; and
hence their chief value. It is not necessary for our readers to trouble
themselves about the meaning of such terms at present; by and by it will
be necessary for them to do so, if they wish to prosecute the study of
any natural science.
But about the Imperial Trochus, with its “orbicularly conical” shell—that
term we may explain as round and cone-like; a reference to Fig. 4, Plate
IV, will shew what is meant by this more clearly than words can, and
likewise exhibit the beautiful markings of this species, with its ground
tint of rich violet brown. This beauty is often obscured by calcarious
incrustations, and marine plants, shewing that the mollusk is sluggish in
its habits—a slothful creature. So it is with human beings, sloth covers
and hides the good qualities and virtues with an overgrowth at all times
difficult to remove, and oftentimes destructive of all that is fair and
good in the character.—Children, be not slothful! The Obelisk Trochus,
(_T. obeliscus_,) is a rare white and green shell, sometimes seen in
collections; it is of a conico-pyramidal form, not remarkable for beauty,
and is a native of the Indian seas.
Mr. Gosse speaks of the Tops and Winkles as among the most useful
inhabitants of the Aquarium; they mow down with their rasping tongues
the thick growth of _Confervæ_ which would otherwise spread like a green
curtain over the glass walls of the tank, and obstruct the view of its
inhabitants. Here is this author’s description of the beautiful piece of
mechanism by which this work is effected:—“The appearance and position
of the organ would surprise any one who searched for it for the first
time, and as it is easily found, and as Periwinkles are no rarities, let
me commend it to your examination. The easiest mode of extracting it,
supposing you are looking for _it_ alone, is to slit the thick muzzle
between the two tentacles, when the point of a needle will catch and
draw out what looks like a slender white thread, two inches or more in
length, one end of which is attached to the throat, and the other, which
is free, you will see coiled in a beautiful spiral manner, within the
cavity of the stomach.
By allowing this tiny thread to stretch itself on a plate of glass, which
is easily done by putting a drop of water on it first, which may then be
drained off and dried, you will find that it is in reality an excessively
delicate ribbon, of transparent cartilaginous substance or membrane, on
which are set spinous teeth of glassy texture and brilliancy. They are
perfectly regular, and arranged in three rows, of which the middle ones
are three-pointed, while on each of the outer rows a three-pointed tooth
alternates with a larger curved one, somewhat boat-like in form. All the
teeth project from the surface of the tongue on hooked curves, and all
point in the same direction.”
And with this curious piece of mechanism the little Winkle works away and
cuts down swathe after swathe of the minute vegetation, just as a mower
does the meadow grass; only the mollusk eats as he goes, and so gets
payment for his labour; the man has it in another and to him more useful
form. We might tell a very long story about these Tops and Winkles, which
are nearly related to each other, but must now pass on to describe the
rest of the shells on Plate IV, which are the Perspective Solarium, (_S.
perspectivum_,) Fig. 5, the generic name comes from _sol_—the sun, and
viewed perspectively, that is, in such a position that the whole top of
the shell is at once presented to the view, looking like a flat surface,
it presents a circular appearance, marked with rings and rays like
representations of the sun sometimes do.
The Variegated Solarium, (_S. variegatum_,) Fig. 6, is a small but very
pretty shell, somewhat rare. The mollusk is remarkable on account of the
singular shape of its operculum, which differs from that of all other
species; it is of a cone-shape, and covered from top to bottom with what
are called membranous lamellæ, that appear to stand out like little
shelves winding up spirally. This singular form of operculum has been
long known to naturalists, but it is not until lately that they have
discovered to what species of testacean it belonged. Let us here explain
that _operculus_ is the Latin for a cover or lid.
CONES, VOLUTES, MITRES, AND OLIVES.
These are names given by collectors to certain classes of univalve shells
distinguished by peculiarities of formation, more or less distinct. We
shall describe two or three of each, that our readers may have some idea
of the meaning of the terms which are often used by those who speak or
write on conchology.