Gasteropoda is a name given by some naturalists to a very extensive group of molluscous animals; the term is derived from two Greek words, signifying stomach and foot;—it has reference to the kind of fleshy foot which generally occupies the whole under side of the body, and by the contraction and extension of the muscles of which, the creature is enabled to glide, with a slow but steady motion, from place to place. The Slug and the Snail are the commonest examples which can be adduced of gasteropods; and one may tell by their slimy tracks, shining like silver in the morning sunshine, that during the night, which is their principal feeding time, they manage to get over a considerable extent of ground, although “a snail’s gallop” is a proverbial expression for slow motion; but it is astonishing how much work of any kind may be done if one “keeps at it;” by doing this the Tortoise beat the Hare, illustrating the truth of the proverb, that “slow and sure wins the race.” If you watch a Snail travelling with its house upon its back, it does not seem to make much way, and you are inclined to think that it will be long ere it reaches the new settlement to which it appears journeying with bag and baggage; but leave the spot for a while, and the chances are that on your return, the “slow coach” will have got somewhere out of sight. Here is a lesson for boys and girls; whatever you take in hand, don’t be in a hurry, and if people say you are “slow,” think of the snail, and keep on!

This, then, is a shelled mollusk of the third class, called Gasteropoda, according to the system of the French naturalist Cuvier. It has a distinct head, which, like the hinder part of the body, which we may call a tail if we like, projects, when the creature is in motion, considerably from the shell; it is also furnished with what we commonly call horns, naturalists say tentacles, from the Latin tento—trying, or essaying; with these the creature, as it were, feels its way; being extremely sensitive; they answer the purpose of organs both of sight and touch; put your finger slowly towards one of them, and you will observe that, even before contact, it begins to retract, or draw in, as though sensible of the approach of some opposing body, as it no doubt is. These horns of the snail, then, are its feelers—eyes to the blind, fingers to the fingerless; so God provides for his creatures all that may be necessary for their existence, and compensates for the deprivation of one sense or organ, by some admirable contrivance which meets the necessities of the case.[1]

THE COMMON SNAIL

Is called by naturalists Helix aspersa, the generic name being derived from a Greek word signifying spiral, and having reference to the shape of the shell; the plural is Helices, a term applied to all convoluted or twisted shells, which terminate in a point like a church spire: a spiral-shelled fossil is called a helicate. The specific name comes from the Latin asper—rough, whence also our English word asperity—roughness, and several others. The Helicidæ, or Helix family, is that which includes the land shell Snails and the naked Slugs, and in this family there are several genera; they are distinguished from the shelled water Snails, both sea and river, by having a different breathing apparatus, and some other points of internal construction which it is not necessary to describe here.

The Common Snail has a mouth, of which it makes good use, as market gardeners well know, and yet this mouth is not furnished with teeth; instead of these, the upper lip, which is of a horny texture, is what is called dentated, from the Latin dentus—a tooth, that is, divided or separated, so as to present somewhat the appearance of a row of teeth in the jaw; this lip is of an arched form, and appears to be a very serviceable kind of instrument to Mr. Helix aspersa, who, if his character be not aspersed, is very destructive to all sorts of greenery. The lower lip is divided only in the middle, where there is an opening of some width: it is not horny, like the upper one.

Snails lay eggs, which are about the size of very small peas; they are soft, and of a whitish colour. Being semi, that is, half, transparent, or clear, their contents can be partly seen; and in those of a water Snail, deposited against the side of a glass bottle, the young were detected with partially formed shells upon their backs.

To shew how tenacious they are of life, it has been mentioned that Mr. S. Simon, a Dublin merchant, had a collection of fossils and other curiosities left him by his father; among these were some shells of Snails, and fifteen years after the collection came into his possession, his son had the shells to play with, and placed them in a basin of water, when lo! out came the slimy bodies and knobbed horns of several of the Gasteropods, no doubt hungry enough after their long sleep.

We all know that our Common Snails hybernate, or sleep through the winter. As soon as the chills of autumn are felt, they seek out some snug crevice in an old wall, or burrow in the earth, or congregate beneath garden pots, roots of trees, thatched roofs, or in any hole or corner that may be convenient, and then throwing a kind of temporary skin, like a drum head, which naturalists call operculum, over the opening of their shells, and sticking themselves fast to the sides of their refuge, or to each other, they sleep away, careless of frosts and tempests.

A moist and rather warm state of the atmosphere seems most congenial to the land Snails, some species of which are found in all countries, except those where the most intense cold prevails. Generally speaking, they do not like dry heat, and to escape from it will get under stones, and into other cool places, from whence a shower brings them forth in such numbers, the smaller species especially, as to lead to the popular belief that it sometimes rains Snails.

These Gasteropods, although extremely injurious to vegetation, must not be regarded as worse than useless, as they commonly are; besides furnishing food for several wild, as well as domesticated, birds, they are no doubt a nourishing article of diet for man. The Romans had their cochlearia, where Snails were regularly fed and fattened for the table; and the French at the present day their escargotoires, or Snailery, for the same purpose; some of the Snails so kept, attain an immense size, as well they may if fed, as by the Romans, on new wine and meal. Many poor persons, especially those who are consumptive, might no doubt derive much cheap sustenance and benefit from using the larger species of Helicidæ, which might be collected from hedges and gardens as food. Why should they not eat those as well as the marine mollusks, such as Oysters, Cockles, Whelks, etc.

Snails have an extraordinary power of re-producing any part which may be injured or cut off, even to the extent of the whole head, as has been observed to be the case; the reparation of injury done to the shell they can effect easily, as can all testaceous mollusks. Respecting the construction of the shell it may be observed that it is produced in the thickness of the mantle, or cloak-like covering which envelopes the body of the animal; the formation commences at the small end or spire, and gradually goes on, whorl upon whorl, as the still widening circles which give the ridgy appearance to most univalves, are called. Columella, or pillar, is the name given to the spire on which the cones are rolled; this is sometimes solid, and sometimes hollow; when the latter, the open end is called the Umbilicus, meaning the navel or centre. The opening at the bottom, from which the animal issues, is the last portion finished, and this is called the aperture, a Latin word adopted into the English dictionary. Some of these Helices are wide and flat, even hollow and cup-like, with the whorls rising above the pillar—these are called discoid shells; others which are long and narrow, with projecting spires, are termed turbinated shells; the former being more or less flat or disk-like, the latter twisted, whirling, like a spinning-top, from the Latin turbo—a whirling, a turning round.

If we take a Common Snail, and plunge it into boiling water, which will instantly kill it, so that it can be removed from the shell, we shall find the whole of that part of the body which was lodged in the upper whorls, or spiral part of the shell, is covered with a thin membrane or skin; this is called the mantle, and that portion of it which corresponds with what we may consider as the back of the mollusk, and which is considerably thickened, is termed the collar; here are situated the glands, which secrete the colouring and other matter of which the shell is mainly composed; although the substance called nacre, or mother-of-pearl, is secreted in the thinner part of the mantle; it is however from the collar that the growth or increase of the shell proceeds. It is in accordance with certain variations in the shape and disposition of this mantle and collar, that shells assume such very different shapes. Sometimes the whorls or spiral ridges, are projected or thrown far out, and this produces the turbinated shell. Sometimes they scarcely rise above each other, but rather spread towards the sides, and then we have the discoid shape. Generally speaking, the whorls of a shell take a direction from left to right, but occasionally an opposite one; they are then called sinistral, or left-handed shells: such are not common. If one of the twisted shells be divided length-ways, it will be seen that the inside of the whorls wind in an ascending direction, round the Columella, or central column, as the spiral staircases in the Crystal Palace.

But let us return to our Garden Snail, who has many near relatives in Britain, several of which have beautifully-marked and convoluted shells, as will be seen by a reference to our coloured illustrations, Plate I. We will introduce them in due order. Fig. 1, the Banded Snail, (Helix nemoralis,) from the Latin nemus—a wood or grove; the prettily-striped shells of this species may be found in great plenty among the roots and in the crevices of the rugged boles of old forest trees, as well as in hedge-rows and in mossy banks, and other situations near woods. Fig. 2, the Heath Snail, (H. ericetorum,) from erica, the Latin for heath; a small species with brown bands, remarkable for its large umbilicus, perforating the centre of the shell nearly through. Fig. 3, the Silky Snail, (H. sericea,) from the Latin sericus—silk-like; the shell of this species is covered with short slimy hairs, which give it a glistening appearance. Fig. 4, the Stone Snail, (H. lapicida,) from the Latin lapis—a stone: Linnæus called the species the Stone Cutter, probably on account of its habit of frequenting stony places, and the peculiar construction of the shell, which has a sharp edge running round each whorl; it is commonly found lodged in the cavities of loose-lying stones, but which it can scarcely be suspected of having hollowed out for its own accommodation.

Fig. 5, the Elegant Cyclostome, (Cyclostoma elegans.) On turning to the 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:—

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.

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.

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.

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

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.

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.

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.

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.

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.

The family of Cones, called Conidæ, is an extensive one, considerably above two hundred species having been discovered. Many of them are very beautiful both in shape and colour, so that they are highly valued by collectors; they are principally found in the southern and tropical seas, upon sandy bottoms, at depths varying from a few feet to seventeen fathoms. The shells are generally thick and solid, rolled up, as it were, into a conical form; the most familiar illustration that can be given of this form is a sugar-loaf, which all these shells more or less resemble in general outline, as thus—

Cones are either plain or coronated, that is, crowned, having rows of projections round the top of the shell, like the second of the above figures; and this forms a mark of division into two classes, although these classes often run, as it were, one into the other; some plain cones having slight irregularities of surface, and some crowned ones being very nearly plain.

The Common, or Ordinary Cone, (Conus generalis,) Plate V. Fig. 1, is an elegantly-shaped and beautifully-marked shell, having much the appearance of being carved out of some rare kind of marble. The Lettered Cone, (Conus littoralis,) Fig. 2, appears to be scribbled over with Hebrew, Greek, or Arabic characters, and almost every species has something peculiar in its markings; clouds and veins, and dots, and stripes, and bands, of every conceivable shape and mode of arrangement, may be met with in these shells, whose surface, when the epidermis, or outer skin is removed, bears a beautiful polish. Curious names have been given to some of them, such, for instance, as the High Admiral, Vice Admiral, and Guinea Admiral, which indicate the rank they hold in the estimation of collectors. From five to twenty guineas is the price at which good and rare ones have been valued, and one, the Conus cedo nulli, which may be translated, the Cone second to none, has fetched the enormous sum of three hundred guineas. It must not be supposed that these shells exhibit all their beauties when, inhabited by a carnivorous, or flesh-eating mollusk, they move slowly about, or lie for a time motionless among the rocks and sand-beds of the ocean. The before-mentioned epidermis, which is the Latin for the outer skin of the human body, covers them like a cloak or mantle, which is the name it bears among naturalists. Much careful labour is required to bring them to a fit state for cabinet shells.

Volutes form an extensive family of shells under the name Volutinæ. The greater part are natives of tropical seas, and dwell far down so that they are seldom found on the coast, except after storms. There are a few European species, but these are not remarkable for beauty, as most of the others are. The generic name signifies twisted, or rather wreathed, as flowers or leaves might be, about some central object. In these shells the spire is generally short, as it is in many cones, sometimes scarcely apparent; the form is usually elegant, and the markings often striking and handsome. On Plate V, will be found three examples—Fig. 3 is the Undulated Volute, (V. undulata,) the Latin for a little wave is undula, and these marks are like the lines caused by the flowing of the waves on a sandy shore: this shell is found chiefly in the South Pacific; the animal which inhabits it is prettily-marked with zebra-like stripes. Fig. 4 is called the Pacific Volute, (V. Pacificus;) the shape, it will be seen, is somewhat different, being more angular, and it is without the waved lines. Fig. 5, the Bat Volute, (V. vespertilio,) is more decidedly knobbed or spiked, approaching nearly to the shape of some of the coronated ones. This species is found in the Indian seas; the specific name is the Latin for a bat.

Mitres; these are usually considered as a genus, or branch of the Volute family; the scientific name is mitra, the form is generally long, slender, and pointed—something like the bishop’s mitre, hence the common name of the genus. In the Episcopal Mitre, (M. episcopalis,) Plate VI, Fig. 1, we see this form in its greatest perfection; this is a handsome shell found in the Indian seas, and on the coasts of the South Sea Islands. The mollusk is remarkable for a long proboscis, double the length of the shell, the extremity of which swells into a club form, and has an oval orifice or opening: the specific name episcopalis, comes from the Latin, and means of, or like a bishop. The Tanned Mitre, (M. adusta,) from the Latin adustus—burned or parched, is, what is called fusiform and turretted, that is, shaped like a spindle, and having a spire or turret-like termination. The streaks of colour are transverse, that is, running the length of the shell, or in other words, they are longitudinal; this, too, comes from the South Sea Islands. Fig. 2 is the Wrinkled Mitre, (M. corrugata,) from the Latin corrugo—to wrinkle; it is very different both in shape and markings, from the last species; the whorls, it will be seen, are angulated or pointed above, and the lower part of the shell is much larger than the spiral or upper portion. It is a true mitre nevertheless, although not just such a one as a bishop would like to wear. It inhabits the Indian Ocean, the coast of New Guinea, etc.

Olives; these, for richness of colour and brilliancy of effect, will bear comparison with any genus of shells. Naturalists speak of them collectively as Olivinæ; they belong to the Volute family, and are said to number about eighty species. Most of those which have reached this country, have come from the Mauritius, where they catch them with lines baited with portions of Cuttle-fish. We have here depicted two of them, namely, the Figured Olive, Fig. 3, (Oliva textilina,) from the Latin textilus, which is woven or plaited; and the Ruddy Olive, Fig. 4, (O. sanguinolenta,) from sanguis—blood.

We must now bring our notice of the Univalves to a conclusion; there are several genera, and many very curious and beautiful species which we have been unable to notice at all, and of those which we have, a short account only could be given; sufficient however, as we trust, to interest our readers in the subject, and induce them to continue the study of it into larger works. Before leaving this division of shells, we would call their attention to one of its greatest ornaments, that is the Ventricose Harp Shell, (Harpa ventricosa,) from the Latin ventriculus—the stomach, applied to this shell on account of its swelled or inflated shape. Nothing, however, can be more elegant than the whole form, nor more beautiful than the markings of this lovely species, (see Plate VI, Fig. 5,) which belongs properly to the Whelk family.

COWRIES.

Of Cowries we have already spoken in our chapter on the Uses of Shells, they are among the commonest of our testaceous ornaments, and are remarkable, especially the foreign kinds, for richness and diversity of colour, and the high polish which they bear. The native species are small plain shells, commonly called Pigs, from some real or fancied resemblance which they bear to the swine; they are pretty little white-ribbed shells, and are tolerably plentiful on various parts of the British coasts. There are three kinds, namely, the Louse Pig, or Nun Cowry, the Flesh-coloured, and European Pig Cowries. The first of these is of a pale reddish colour, with six square black spots on the back; the second is a beautiful rose tint; and the third is ash-coloured or pinkish, with three black dots, and a white streak down the back. The Money Cowry, (Cypræa moneta,) used as current coin in many parts of India, as well as on the coast of Guinea, is a yellow and white shell, with a single band of the former colour; it is small of size, and is sometimes called the Trussed Chicken, for the same reason as the term Pigs is applied to its British relatives. These Cowries are obtained principally about the Phillippine Islands, the Maldive Islands, and the coast of Congo, where, after high tides, the women collect them in baskets mixed with sand, from which they are afterwards separated and cleaned, when they are ready for the market.

They are only useful as coin so long as they remain unbroken. The value of a single shell is very small, as the following table will shew:—Four Cowries make one gunder; twenty Gunders one punn; four Punns one anna; four Annas one cahaun; and four Cahauns one rupee. The value of the latter coin is equal to two shillings and threepence, English money, and this would be exchangeable for five thousand one hundred and twenty Cowries; so that it would never do to pay large sums in this kind of coin: a waggon would be required to convey a few pounds with. In this country the Money Cowries are frequently used as markers or counters in social games; they are generally white, in shape rather broad and flat, being much spread out round the edges, which are slightly puckered, like frills. Here are two figures of the shell, exhibiting the back and front view.