Chapter III: Introduction: What Are Shells? (3)

It is to the _Mytilidæ_ family that we shall first direct our attention, and here we find the Common or Edible Mussel, (_M. edule_,) and many other species, in all of which the shell is more or less elongated, or lengthened out, and pointed at one end. The members of this family are abundant on most rocky coasts, where facilities are afforded for the mollusks to moor themselves to rocks, stones, and other substances covered at high-water, but left dry by the retreating tide. They are not, however, confined to shores of this description, but are sometimes found in vast numbers on low sandy or pebbly flats, which run far out into the sea; these are called beds of Mussels, and are, like the Oyster grounds, specially cared for and protected. As a ship by its cable, so commonly the Mussel, by its bissus or beard, is made fast to its anchorage-ground, be it pebbly or sandy beach, or jutting rock. Sometimes, however, the mollusk travels, and this is how it manages to do so; it has a stout fleshy foot, in shape something like that of a chubby child, and this it can advance about two inches beyond the edge of the shell, then fixing the point of it to a piece of rock or any other body, and contracting it, the shell is drawn onward, and sure, though slow, progress is made in any desired direction. The _Pinna_, as the marine Mussel is called, has a foot which is cylindrical in shape, and has at the bottom a round tendon, almost as long as itself, the use of which appears to be to gather in and retain the numerous threads with which, when inhabiting the shores of tempestuous seas, it lashes itself fast to the fixed objects around; these threads are fastened at various points, and then drawn tight by the animal, whose instinct teaches it that its brittle shell would soon be broken in pieces, if suffered to roll hither and thither at the mercy of the waves.

The Mussel has a very curious method of preparing its cable for this service; it is not woven, nor spun, nor drawn out of the body, like the web of the spider, but produced in a liquid form, and cast in a mould which is formed by a groove in the foot, extending from the root of the tendon to the upper extremity; the sides of this groove are formed so as to fold over it and form a canal, into which the glutinous or sticky secretion is poured; there it remains until it has dried into a solid thread, when the end of it is carried out by the foot, and applied to the object to which it is to be attached; the canal is then opened through its whole length to free the thread, and closing again is ready for another casting; as if conscious how much depends upon the security of his lines, the animal tries every one after he has fixed it by swinging itself round so as to put the threads fully on the stretch; when once they are all firmly fixed, it seems to have no power of disengaging itself from them; the liquid matter out of which they are formed, is so very glutinous, or glue-like, as to attach itself firmly to the smoothest bodies. The process of producing it is a slow one, as it does not appear that the _Pinna_ can form more than four or five in the course of twenty-four hours. When the animal is disturbed in its operations, it sometimes forms these threads too hastily; they are then more slender than those produced at leisure, and, of a consequence, weaker. On some parts of the Mediterranean coast, as in Sicily, gloves and other articles have been manufactured from the threads of this mollusk; they resemble very fine silk in appearance.

The foot of the Cockle, of which we here give a figure, is commonly employed in scooping out the mud or sand, beneath which it conceals itself; this useful limb assumes the form of a shovel, hook, or any other instrument necessary for the purpose; it appears to be a mass of muscular fibres, and to possess great power. As a boatman in shallow water sends his vessel along by pushing against the bottom with his boat-hook, precisely so does _Mr. Cardium_ travel; he doubles up his foot into a club, and by an energetic use of it as a propeller, makes considerable headway along the surface of the soft sand beneath the waters. In this way, too, some members of the genus _solen_ force their way through the sand; while those called _Tellina_ spring to a considerable distance, by first folding the foot into a small compass, and then suddenly expanding it, closing the shell at the same time with a loud snap; so that you see these sober-looking mollusks are sometimes frolicksome fellows; this is an enforcement of the lesson, judge not by appearances.

Some of the species, both of the Mussel and Cockle families, have very beautiful shells. We give a representation of one of each, on Plate VIII. Fig. 2 is the Magellanic Mytilus, (_M. Magellanicus_,) found chiefly in the Straits of Magellan; it is generally four or five inches long, the shells when polished are very brilliant, the deep purple colour changing into rich violet, as they are held in different lights. In most cabinets the large fan-like delicate shells of the genus _Pinna_ may be observed; the largest species is that called _Pinna flabellum_, taken in the Mediterranean; it sometimes exceeds two feet in length. The first of these names is a Latin word signifying, besides a shell-fish, the fin of a fish, or the wing feathers of a bird—hence the term pinion; it refers to the fin-like or wing-like shape of this shell. _Flabellum_ means a fan, referring probably to the bissus of the mollusk, which is fine and glossy, like silk, and very abundant.

Many pretty specimens for figuring might be selected from the _Naidæ_, a family of Fresh-water Mussels, so called from the Naiades, fabulous divinities of the streams and rivers. The shells of many of these, which are of considerable thickness, are lined with the most brilliant nacre, and in these, as might be expected, pearls are sometimes found. One species, abundant in some English rivers, called the _Mya Margaritifera_, or, as some say, _Uno elongates_, has long been celebrated for this valuable production. It was most likely with pearls from this mollusk that Julius Cæsar adorned a breast-plate, which he dedicated to Venus, and hung up in her temple. The rivers Esk and Conway were formerly celebrated as British pearl-fishing grounds; a Conway pearl was presented by her chamberlain, Sir Richard Wynn, of Gwyder, to Catharine, Queen of Charles the Second; and in the royal crown of Britain this jewel is said still to occupy a place. Sir John Hawkins, the circumnavigator of the globe, held a patent for the pearl-fishery of the River Irt, in Cumberland. The rivers of Tyrone and Donegal, in Ireland, have, or had, their pearl-bearing Mussels; we read of one which weighed thirty-six carats, (a carat is nearly four grains,) but not being of perfect shape and colour, it was only valued at forty pounds. We also read of another purchased by Lady Glenlealy, for £10, and found to be so perfect and admirable, that £80 was afterwards offered for it, and refused.

These _Naidæ_ have not a bissus like the Marine Mussels, they are therefore never attached to one object; they use their foot as a propeller in traversing the muddy floor of the pond or river, and they have a very funny way of getting along indeed; first, they open the valves of the shell, put out the foot, and after some little hard work, manage to set themselves up on edge; they then proceed by a series of jerks, leaving a deepish furrow in the mud behind them.

We will now go to Fig. 3, the Spined Cytherea, the _Cytherea_ or _Venus Dione_ of naturalists; the meaning of the term is the mother of Venus, who was, as you will remember, the goddess of beauty, given to this shell perhaps because it is entitled to occupy a place at the head of the _Cytherea_, a genus of the _Cardiidæ_, or Cockle family, of which genus there are about seventy-eight living species; this, as it is the most rare, is also, perhaps, the most beautiful; it is found in the seas of America, and is remarkable for the row of spines on the hinder border of each valve; these vary much in size and number, being in some individuals long and far apart, in others, short, thick, and closely set. The colour of the shell also varies considerably, being sometimes of a delicate rose colour; at others, more of a claret; at others again, bordering on purple. It was for one of the first discovered specimens of this shell, that £1000 is said to have been given. Truly a Venus of value this; it ought to be called the Queen of Cockles!

Our next example, (see Fig. 4,) is the Spotted Tridacna, (_T. maculatus_,) the latter term signifying spotted. In the _Chamidæ_ or Clam family, is placed the _Tridacna_ genus, the discovered species of which are not numerous; they are chiefly found in the Indian seas. The one above mentioned claims pre-eminence for beauty. We cannot quite see the applicability of the generic name; _Tridacnus_, in Latin, signifies to be eaten at three bites, but he must be a man of large capacity indeed who could so devour the head of this family, the Giant Tradacna, (_T. gigas_,) a single specimen of which has been known to weigh as much as five hundred and seventy pounds; from three to four hundred is by no means an uncommon size. The shell of this giant mollusk is of a very picturesque shape, something like its spotted _congener_, as we call anything of the same kind or genus, only it is somewhat plainer, and more deeply ribbed and indented. The inside is of a glossy whiteness, and it is frequently used as a basin for garden fountains, or the reception of rills or little jets of water, which sparkle in its stainless hollow. In the church of St. Salpice, at Paris, is a shell of this immense Clam, the valves of which are used as receptacles for holy water; it was presented to Francis the First, by the republic of Venice. Fancy the clapping to of such a pair of valves, when the animal closes its shell in alarm, and the strength of the cable required to moor it to the rocks or coral reef. The spotted species here figured has a solid and heavy shell, very elegantly shaped, and beautifully marked, as will be seen; the greatly reduced size of the figure prevents anything like justice being done to the original.

The above is a figure of the Heart Isocardea, (_I. cor_,) which is also a member of the Clam family, and one of the most elegantly-shaped shells in the whole range of Conchology. It is a native of the Mediterranean and other seas of Europe, and has been taken in deep water on the West coast of Ireland. We complete this group with a representation of the curious _Arcadæ_ family, or Ark shells, as they are commonly called, because one of the species was thought to resemble the ark built by Noah. Mr. Swainson tells us that the animals of these shells affix themselves to other bodies by a particular muscle, which is protruded through the gaping part of the valves; they also adhere, when young, by means of the bissiform epidermis, or bissus-like outer skin: this species is a native of the Atlantic Ocean and the seas of Europe. The Antique Ark, (_A. antiqua_,) is very like the Common Cockle, being of a white colour, and heart-shaped. We give below a representation of this shell, and also of the shell of the pretty little Pearly Trigonia, (_T. margaritacea_,) included in the _Arcadæ_ family; this is a rare species, found only in the seas of New Holland.

SCALLOP SHELLS.

Several species of Scallop Shells are found scattered about on our shores; they belong, as before stated, to the family _Pectinidæ_, the meaning of which term has been already explained. These shells were called by Cuvier “the Butterflies of the Ocean,” on account of the various and beautiful colours which they exhibit. Some of them are exceedingly thin, and brittle as glass; one species found in the Arctic regions, is as transparent as that substance, and is therefore called _P. vitreus_, from the Latin for glass, which is _vitreum_. One of the commonest of our native Scallops is the St. James’ Cockle, (_P. Jacobœus_;) this shell is found in great plenty along our southern coasts; it is often referred to by old writers, on account of having been commonly worn in the hats of pilgrims to Palestine, or the Holy Land, as the scene of our Saviour’s life and death was called. Sir Walter Raleigh, in his poem called “The Pilgrimage,” thus enumerates the different articles considered necessary for a Palmer, as these pilgrims were termed:—

“Give me my _scallop shell_ of quiet,
My _staff_ of faith to lean upon,
My _scrip_ of joy, (immortal diet,)
My _bottle_ of salvation,
My _gown_ of glory, hope’s true gage,
And thus I’ll make my pilgrimage.”

This Mollusk, it may be noticed, like many other bivalves, has a flat, and a concave or hollow shell: in early times when plates and drinking vessels were not so plentiful as they are now, one of these served the former purpose, and the other the latter; thus, in speaking of a feast, a Gaelic or Scottish bard has said—

“The joy of the _shell_ went round.”

Sometimes the species termed _Pecten opercularis_, was used as the pilgrim’s badge; the specific name comes most likely from the Latin _operculum_, whose meaning has been explained.

This too, is a common British shell, as is also the little speckled Scallop, (_P. varia_,) which may be found on almost any part of the coast where the water-line is margined with a sandy ridge. The shells are generally about two inches long, of various colours, clouded, speckled, and marked with about twelve ribs. There is a foreign species called the Flounder Scallop, _P. pleuronectes_, which is remarkable for having the two valves of the shell of different colours, the upper one being of a rich reddish brown, and the lower one white: the specific name has reference to this, being compounded of the Latin _pleura_—something double, and _necto_—to join. The fish called the Flounder, is brown above and white beneath, hence the English name of this shell. The preceding engraving of the Common Scallop, viewed from the front, shows the flat and concave form of the two valves of this shell, and also the depth of the indentations or ridges.

LIMPITS.

Among the rocks of the British coast, there are no shells more frequently met with than those of the Common Limpit, _Patella vulgata_; they lie scattered about like so many little empty cups, each having, on the death of the mollusk, fallen from the rocky cavity in which it was embedded, and which was just large enough to contain it. Here the animal attaches itself so firmly by its fibrous foot, which is hollow in the centre, and acts like a sucker, that it is almost impossible to loosen its hold otherwise than by inserting something thin, like the blade of a knife between it and the stone. By this power of adhesion, the Limpit is protected from the violence of the waves, and also from its numerous enemies, aquatic birds and animals, which have a relish for its flesh. Still vast numbers are used as food, both by man and the inferior creatures, so that the means of defence furnished to the Limpits of the rock, are not always sure. “The peasantry of the western isles of Scotland,” we are told by Miss Pratt, “look to the Periwinkles and Limpits, which abound on the rocks, for their daily meal, often for long seasons, subsisting almost entirely upon this humble food. In the Isle of Skye, the inhabitants are often, at one time of the year, without any other source of provision.” Then comes the Sea-gull, and the Duck, and the Pied Oyster-catcher, to feed on the poor little mollusk, the bill of the latter bird being admirably adapted for loosening its hold on the rock.

_Patella_ in Latin signifies a salad-dish, a knee-pan, and several other domestic utensils, of a broad shallow make, and hence we find the plural form of the word applied to the Limpit family, whose shells are of such a shape. Members of this family are found on all rocky coasts, except those of the Arctic seas; on Tropical rocks they grow to a large size, and form a valuable article of food. A very curious piece of mechanism is the tongue of the Common Limpit, it is from two to three inches long, and has a spoon-like extremity, so that it looks, when extended from the mouth, like a small snake; if examined through a microscope, it is seen to be armed throughout its whole extent with rows, four deep, of sharp hooked teeth, and between each row are placed two others, which have three points, and are set in a slanting position; the use of this arrangement we cannot at present determine, but no doubt it has a perfect adaptation to the wants of the animal.

There are shell-fish called Key-hole Limpits, which belong to the genus _Fissurellidæ_, from _fissura_—a cleft or slip, from whence comes also fissure. All the members of this genus are distinguished by the aperture at the top of the shell, shaped like a key-hole, which is situated exactly over the breathing organs, and serves as a channel for the water necessary for respiration.

Frequently upon the fronds of the large olive sea-weeds may be found a tiny shell shaped something like that of the Common Limpit; it is of an olive green colour, with blue streaks, and is called, from its clearness, the Pellucid Limpit, _P. pellucida_. There is also another much like it in appearance, which naturalists call _P. lœvis_. To the labours of these little mollusks, according to Dr. Harvey, may be partly attributed the destruction of the gigantic Algæ, (sea-weed.) Eating into the lower part of the stems, and destroying the branches of the roots, they so far weaken the base, that it becomes unable to support the weight of the frond; and thus the plant is detached and driven on shore by the waves.

“And so the forest tall that groweth,
Underneath the waters clear,
Does the little woodman mollusk,
Level every year;
From small causes, great results—
Teaching you to persevere.”

ROCK-BORERS.

The family _Pholadæ_ comprises a group of mollusks, the boring habits of which have long been known; they penetrate wood, hard clay, chalk, and rocks, and devastate the labours of man; they attack the hulls of ships, the piles which form the foundations of piers and break-waters, and they force themselves upon our attention by the loss of property, as well as of life, which results from their hidden depredations. Of this family, those belonging to the genus _Pholus_ may be more especially likened to the Edomites of Scripture, because they take up their abode in the rock, and hollow out for themselves dwellings therein. With a shell as thin as paper, and brittle as glass, the wonder is how these Rock-borers work their way into and through hard stones. Some naturalists assert that they effect this by means of an acid which decomposes the substance of the rock, and renders it soft; others, that the animal keeps turning round and round like an instrument called an auger, and so gradually rasps away the surface of the stone with the angles of its shell, but we question whether the shell would not be worn out first in such a process. The generic name of these “stone-piercers,” comes from the Greek word _Pholeo_—to hide, and the rocky chambers which they hollow out for themselves, are as snug hiding-places as can well be imagined; yet, however deep they may go into these gloomy caverns, as we should be apt to suppose them, they need not be in darkness, for it appears that these Pholades emit a most remarkable light, whether phosphorescent or not does not appear to be determined; so strong is it, that it is said to illuminate the mouth of the person who eats the mollusk; and it is remarked by Dr. Priestly, that “contrary to the nature of most fish, which give light when they tend to putrescence, this is more luminous the fresher it is, and when dried its light will revive on being moistened with water.” So that in more respects than one these rock-borers are mysteries. The most common of them, perhaps, is the Prickly Pidduck, or Peckstone, (_P. dactylus_,) which is much used by the fishermen of our coasts as bait; the specific name is the Latin for a fruit shaped like a finger, which is something like the shape of this mollusk, as will be seen by the annexed engraving.

The genus _Pholus_ is very widely distributed, and all the species have the same boring habits as those of our own coast, which we need not enumerate. Like them too in this respect are the marine worms called _Teredo_, which make their way into the bottoms of ships, and all submerged timber, but these will be more fully spoken of in another volume. The above figure exhibits the _Pholas dactylus_ as it appears in a section of rock, split open for the purpose of seeing the shelly miner at his work.

MULTIVALVES.

We have insensibly passed from the Bivalve shells to those composed of several pieces, and therefore called Multivalves; properly, perhaps, the Rock-borers, last described, come into this division, for although their covering consists mainly of two principal portions or valves, yet there are often additional parts; in some a calcarious tube envelopes the whole mollusk, leaving only an opening behind; this is more especially the case with those which most resemble worms, such as the genera _Teredina_ and _Teredo_, included by Lamarck in the family which he calls _Tubulidæ_.

The first group of multivalves we shall have to notice, are

THE CHITONS,

forming the family _Chitonidæ_. The term has a Greek derivation, and means a coat of mail. These mollusks are covered by a shell formed of eight distinct portions, arranged along the back in a single row, and attached to a mantle which resembles leather, being very tough and wrinkled; the edges of this mantle extend beyond the borders of the plates, which overlap each other, so as to constitute a kind of armour, very different from the conical shell of the Limpit, or the turbinated, that is twisted, case of some of the Borers. The coverings of the Chitons are variously marked, so that each distinct species is known by its peculiar pattern, as a knight of old by the quarterings of his shield. All the mantles, however, have scaly, hairy, or spiny margins. In this coat of mail, the animal can roll itself up like an armadillo, and so be tolerably secure from its enemies; it has an oval foot, the sides of which are covered with small leaflets, and by means of this it can attach itself to rocks, like the Limpit, or travel about in search of adventures. It has no distinct head, therefore it is _acephalous_; nor any perceptible eyes. The mouth is furnished with a long tongue, curled up spirally, like a watch-spring, and armed with horny teeth.

The members of the Chiton family are numerous, being found on most rocky shores; they attain the largest size in the hottest climates, having never been found very far north. The British species are small, and not more than two or three in number; they may be found adhering to stones near low-water mark. We give a figure of one of these called the Tufted Chiton, (_C. fascicularis_;) this word is from the Latin _fasciculus_—a little bundle of leaves or flowers, and it refers to the hairy tufts that edge the mantle of this marine slug.

BARNACLES,

Or, as they are sometimes called, Bernicles, belong to what naturalists term the class _Cirrhopoda_, sometimes spelled _cirripeda_, which appears to be derived from the Latin _cirrus_—a tuft or lock of hair curled, and _pede_—a foot; hence the term may be translated hairy-footed. Such of our readers as have seen the Common or Duck Barnacle, (_Pentalasmis anatifera_,) will at once understand the applicability of this term. Many a piece of drift wood comes to land literally covered with long fleshy stalks, generally of a purplish red colour, twisting and curling in all directions, and terminating in delicate porcelain-like shells, clear and brittle, of a white colour, just tinged with blue, from between which project the many-jointed _cirrhi_, or hair-like tentacles, which serve the purpose of a casting net, to seize and drag to the mouth of the animal, its prey, which consists of small mollusks and crustacea.

This is the Barnacle about which such strange stories are told by old writers, who affirmed that the Barnacle or Brent Goose, that in winter visits our shores, is produced from these fleshy foot-stalks and hairy shells by a natural process of growth, or, as some philosophers of our day would say, of development. Gerard, who, in 1597, wrote a “Historie of Plants,” describes the process by which the fish is transformed into the bird; telling his readers that as “the shells gape, the legs hang out, that the bird growing bigger and bigger the shells open more and more, till at length it is attached only by the bill, soon after which it drops into the sea; there it acquires feathers, and grows to a fowle.” There is an amusing illustration given in Gerard’s book, where the young Geese are represented hanging on the branches of trees, just ready to drop into the water, where a number of those that have previously fallen, like ripe fruit, and attained their full plumage, are sailing about very contentedly. It was part of this theory that the Barnacles were of vegetable origin, they grew upon trees, or sprung out of the ground like mushrooms; so we find in the works of an old poet named Du Bartas, these lines:—

“So slow Bootes underneath him sees
In the icy islands goslings hatched of trees,
Whose fruitful leaves, falling into the water,
Are turned, as known, to living fowls soon after;
So rotten planks of broken ships do change
To Barnacles. O transformation strange!
’Twas first a green tree, then a broken hull,
Lately a mushroom, now a flying Gull.”

The investigations of modern science have quite exploded this foolish notion; we now know exactly what transformations the Barnacle undergoes; strange enough some of them are, but it does not change into a Goose, although its specific name has reference to that bird, being derived from _anas_, the Latin for Goose.

The shell of the Barnacle is composed of five pieces joined together by membranes; four pieces are lateral, that is to say, they form the sides, the word comes from the Latin _latus_—a side; the other is a single narrow slip, which fills what would otherwise be an open space down the back between the valves; these parts of the shell appear to be somewhat loosely connected, so as to allow free action to the animal lodged within, which is enclosed in a fine skin or mantle. The mouth is placed at the lower part, near the opening, whence the _cirrhi_ issue forth; this mouth is a curious piece of mechanism, being furnished with a horny lip covered with minute _palpi_, or feelers; there are three pairs of _mandibles_, that is jaws, the two outer ones being horny and _serrated_, that is jagged or toothed like a saw; the inner one is soft and membranous, that is, composed of little fibres, like strings, crossing each other, as we see what are called the veins in a leaf.

Much more might be said about the internal structure of the Cirrhopods, or _Balani_, as the Barnacle group is sometimes called, from the Latin _Balanus_—a kind of acorn. By some naturalists, the term is not applied to the stalked _Cirrhipoda_, like that we have been describing, but only to the _sessile_ kinds, that is, those which set close or grow low; from the same Latin root comes the English word _session_—a settling. The coverings of these Dwarf Barnacles are sometimes called acorn shells; they are commonly white, of an irregular cone shape, composed of several ribbed pieces, closely fitted together with an opening at the top, closed by an _operculum_, or stopper.

These shells cover in patches the surface of exposed rocks, drift wood, and any other substance. Some of the mollusks affix themselves to the bodies of Whales, others form a lodgment in the hollows of corals and sponges. Once fixed they remain so during life, taking their chance of such suitable food as may come within their limited sphere of action. At an earlier stage of their existence, both their shape and habits are very different, being lively little creatures, swimming about hither and thither like water-fleas. They are about the tenth of an inch long, and of most grotesque appearance, having six jointed legs set with hairs, the whole being so arranged that they act in concert, and striking or flapping the water, send the little body along in a series of bounds; then the creature has two long arms, each furnished with hooks and a sucker, and a tail tipped with bristles, which is usually folded up under the body; its pair of large staring eyes are _pedunculated_, that is, set upon foot-stalks; it has a house on its back, like a bivalve shell, into which it can collect its scattered members when occasion requires. When of sufficient age to settle itself in life, and become a staid member of submarine society, it fixes itself to some convenient object, throws away its eyes as no longer useful, gets rid of its preposterous limbs, enlarges its house, and sits down to fishing in a small way for an honest and respectable livelihood.

A piece of timber covered with Stalked Barnacles, wriggling and twisting about like so many helmeted snakes, and waving their plume-like _cirrhi_, is a very curious sight. They sometimes attach themselves to ship’s bottoms in such numbers as to retard their progress through the water; they do not, however, bore into and destroy the timber, like the _Teredines_, or ship worms, to which we have alluded in our brief notice of the _Pholadæ_. The growth of Barnacles must be very rapid, as a ship perfectly free from them, will often return after a short voyage, with her bottom below the water line completely covered.

We give a representation of a group of these stalked mollusks, as they appear affixed to a piece of timber. This is the Common, or Duck Barnacle.

CUTTLE FISH.

Strange and monstrous as are the forms of many of the creatures that inhabit the deep, there are perhaps none more so than those belonging to that division of the class _Cephalopoda_, called _Sepia_ or Cuttle-fish. But before we go any further let us enquire what is meant by a _Cephalopod_. Our readers have already learned that _Gasteropod_ means stomach and foot, and that _acephalous_ means headless; now here we have a word which takes a portion of each of the others, _cephal_—head, and _peda_, or _poda_—a foot, consequently _ceph-a-lo-po-da_, is a class of molluscous animals which have their feet, or organs of motion, arranged around the head, something, you may suppose, like that celebrated hero of nursery rhymes,

“Tom Toddy, all head and no body.”

Only our bag-shaped Mr. Sepia, with his great round staring eyes, and numerous legs or arms, whichever you please to call them, all twisting and twining about like so many serpents, is a much more formidable looking individual. A strange fellow is this altogether; he has a shell, but he does not use it for a covering, he carries it inside of him, and it serves the purpose of a sort of back-bone; it is horny and calcarious, light and porous, as our readers well know, having most likely often used it to take out unsightly blots, or erase mistakes in their copy or cyphering books.

When Mr. Sepia walks abroad, he sticks his little round body upright, so that his eyes, and mouth, which is armed with a parrot-like beak, are brought close to the surface over which he passes, while his long twining legs go sprawling about in all directions; on the insides of these legs are a great number of small circular suckers, by means of which the animal can fix itself to any object so tightly that it is almost impossible to detach it without tearing off part of the limb. Woe be to the poor unfortunate fish that chances to come in its way; the snaky arms are thrown around it, and made fast, and away goes the cephalopod for a ride, eating on the road to lose no time, on the finny steed that carries it. In some species each of the suckers has a hook in the centre, which of course renders the hold yet firmer, and no doubt adds to the disagreeable sensation which their tight compression must cause; it is likely that these hooks are intended to retain the hold of soft and slippery prey, which might otherwise be too agile for the “ugly customer,” that would affectionately embrace it. But Mr. Sepia, though well armed in front, is rather open to attacks in the rear of his soft naked body; to provide for such an emergency, he is furnished with a little bag of inky fluid, which he squirts out in the face of his pursuer, and escapes under cover of the cloud; this is the substance used by painters, and called sepia, whence the generic name of the mollusks which produce it.

In the British seas none of these cephalopods attain so large a size as to be formidable to man, as they do in warmer climates. It was asserted by Dens, an old navigator, that in the African seas, while three of his men were employed during a calm in scraping the sides of the vessel, they were attacked by a monstrous Cuttle-fish, which seized them in its arms, and drew two of them under water, the third man was with difficulty rescued by cutting off one of the creature’s limbs, which was as thick at the base as the fore-yard of the ship, and had suckers as large as ladles; the rescued sailor was so horrified by the monster, that he died delirious a few hours after. An account is also given of another crew who were similarly attacked off the coast of Angola; the creature threw its arms across the vessel, and had nearly succeeded in dragging it down, and was only prevented doing so by the severing of its limbs with swords and hatchets. A diligent observer of nature has asserted that in the Indian seas Cuttle-fish are often seen two fathoms broad across the centre, with arms nine fathoms long. Only think, what a monster! with a body twelve feet across, and eight or ten legs like water-snakes, some six and thirty feet long. Well may it be said, that the Indians when they go out in boats are in dread of such, and never sail without an axe for their protection.

There is a story told by a gentleman named Beale, who, while searching for shells upon the rocks of the Bonin Islands, encountered a species of Cuttle-fish called by the whalers “the Rock-squid,” and rashly endeavoured to secure it. This cephalopod, whose body was not bigger than a large clenched hand, had tentacles at least four feet across, and having its retreat to the sea cut off by Mr. Beale, twined its limbs around that gentleman’s arm, which was bared to the shoulder for the purpose of thrusting into holes of the rocks after shells, and endeavoured to get its horny beak in a position for biting. The narrator describes the sickening sensation of horror which chilled his very blood, as he felt the creature’s cold slimy grasp, and saw its large staring eyes fixed on him, and the beak opening and closing. He called loudly for help, and was soon joined by his companion, who relieved him by destroying the Cuttle-fish with a knife, and detaching the limbs piece by piece.

There are several species of these cephalopods; the most generally distributed appears to be the _Octopus vulgaris_, or Common Cuttle-fish, which is sometimes found on our own shores, where also may be obtained the Common Sepiola, _S. vulgaris_, usually about three inches long, and the Officinal Cuttle-fish, _S. Officinalis_, which is about a foot in length; we give below small figures of each of these three species, to show the difference in the shape: the two last, it will be observed, have, in addition to the eight tentacles, which give the generic name _Octopus_, signifying eight, two long side arms, the use of which does not appear to be very clearly determined.

NAUTILUS AND AMMONITE.

The Nautili are called testaceous cephalopods, our readers know, or ought to know, the meaning of both these terms. Like the Cuttle-fish they are sometimes called _Polypi_, because they have many arms or tentacles, the word _poly_, with which a great number of English words commence, being the Greek for many. An ancient writer named Aristotle, after describing the naked cephalopods, says, “There are also two polypi in shells; one is called by some, _nautilus_, and by others, _nauticus_. It is like the polypus, but its shell resembles a hollow comb or pecten, and is not attached. This polypus ordinarily feeds near the sea-shore; sometimes it is thrown by the waves on the dry land, and the shell falling from it, is caught, and there dies. The other is in a shell like a snail, and this does not go out of its shell, but remains in it like a snail, and sometimes stretches forth its _cirrhi_.” The first of these animals, there can be no doubt, is the Argonaut, or Paper Nautilus, and the latter that which is called the True Nautilus, of both of which species let us say a few words, which we will introduce by quoting some beautiful lines from a poem called “the Pelican Island,” by James Montgomery.

“Light as a flake of foam upon the wind,
Keel upwards from the deep, emerged a shell,
Shaped like the moon ere half her orb is filled:
Fraught with young life it righted as it rose,
And moved at will along the yielding water.
The native pilot of this little bark
Put out a tier of oars on either side;
Spread to the wafted breeze a two-fold sail,
And mounted up and glided down the billow,
In happy freedom, pleased to feel the air,
And wander in the luxury of light.”

The tiny mariner here alluded to, is the Paper Nautilus, common in the Mediterranean and some tropical seas; its scientific name is _Argonauta argo_. In the mythology, we read that _Argo_ was the name of a ship that carried a certain Grecian named Jason, and a crew of _argives_ in search of adventures; some say that the term is derived from a Greek word signifying swift: this party of mariners, said to be the first that ever sailed upon the sea, was called _Argonauts_, or, as it might be freely translated, seamen of the ship Argo. _Nauticus_, in Latin, signifies anything relating to ships or navigation, and here you have the whole origin of the name of this little Argonaut, about which we must sing you a song written by Mary Howitt, before we proceed further:—

“Who was the first sailor; tell me who can;
Old father Neptune?—no, you’re wrong,
There was another ere Neptune began;
Who was he? tell me. Tightly and strong,
Over the waters he went—he went,
Over the waters he went!

Who was the first sailor? tell me who can;
Old father Noah!—no, you’re wrong,
There was another ere Noah began,
Who was he? tell me. Tightly and strong,
Over the waters he went—he went,
Over the waters he went.

Who was the first sailor? tell me who can;
Old father Jason?—no, you’re wrong,
There was another ere Jason began,
Don’t be a blockhead, boy! Tightly and strong,
Over the waters he went—he went,
Over the waters he went.

Ha! ’tis nought but the poor little Nautilus—
Sailing away in his pearly shell;
He has no need of a compass like us,
Foul or fair weather he manages well!
Over the water he goes—he goes,
Over the water he goes.”

Many more poems of the like nature we might quote, for this little shelled cephalopod has been a favourite with the poets time out of mind, and in some instances they and the less imaginative naturalists have disagreed in their accounts of its form and operations, for instance, Pope says—

“Learn of the little Nautilus to sail,
Spread the thin oar and catch the driving gale.”

“Catch a fiddle-stick,” say some naturalists, the little Nautilus does nothing of the sort; and if you go to him to learn navigation, you will never be much of a sailor; he may teach you how to sink to the bottom and rise again, and that kind of knowledge might be worth something to you if you could breathe under water; and he might teach you how to swim, but not how to sail, for in spite of all poetic theories, he does the former and not the latter. Most usually he walks about at the bottom of the sea on his long arms, something like the Cuttle-fish, feeding on the marine vegetation; the shell is then uppermost; if we could look inside of it we should see numerous little chambers or cells, the larger and outermost of which only are inhabited by the mollusk, the others being filled with air render the whole light and buoyant. Through the centre of these chambers, down to the smallest of them, runs a membranous tube which can be exhausted or filled with fluid at the pleasure of the animal, and the difference thus effected in the weight of the shell enables it to sink or swim; in the latter case, up it goes to the surface, and “keel upwards from the deep,” emerges, as the poet has said, but once there it soon reverses its position. The shell becomes like a boat it is true, but its inhabitant neither points a sail nor plies the oar, but propels itself along stem foremost by a muscular action, which by alternately compressing and loosening a kind of siphon, throws out jets or gushes of water, which by the resistance they meet with from the surrounding fluid, give the desired onward motion, and away the swimmer goes, his long arms gathered closely together, and streaming behind like the tail of a comet, and its round eyes keeping a sharp look-out on either side. Should it espy danger, the body and limbs are withdrawn into the shell, and the fluid driven through the central tube, so as to compress the air in the pearly cells, and down sinks the swimmer once again to his native depths, where

“The floor is of sand like the mountain drift,
And the pearl shells’ spangle the flinty snow;
And from coral rocks the sea-plants lift
Their boughs where the tides and billows flow,
The water is calm and still below.
For the winds and waves are absent there;
And the sands are bright as the stars that glow
In the motionless fields of upper air.
And life in rare and beautiful forms,
Is sporting amid those bowers of stone,
And is safe, when the wrathful spirit of storms,
Has made the top of the waves his own.”

We give below two figures of the Argonaut, one of which represents him crawling at the bottom of the sea, and the other swimming on the surface.

The True, or Pearly Nautilus, (_N. Pompilius_,) the origin of whose specific name we have been unable to discover, is much like the Argonaut in appearance and general construction; the shell is externally smoother and more iridescent, it is also generally somewhat thicker than the former kind, and has internally more chambers or divisions; its pearly lustre renders it a beautiful ornament, and the large size it frequently attains a very conspicuous one. Its inhabitant has several peculiarities of organization, which distinguish it from the Argonauts, but into these we need not enter; neither can we pause to describe the other species of nautili, the shells of which, like those of the Cowry and other univalves, are covered with a membrane which hides their beauty. This membrane or mantle sometimes extends some distance beyond the edge of the shell, and, being of a light and filmy appearance, may have been mistaken for a sail hoisted by the creature to catch the breeze, while its long arms, thrust up into the air or down into the water, may have been thought to be masts or oars, so that the poets are not so much to be blamed, if they say as Wordsworth does.

“Spread, tiny Nautilus, the living sail,
Dive at thy choice, or catch the freshening gale.”

Nearly allied to the Nautili are these beautiful fossil shells called Ammonites, from their fancied resemblance to the horns of a heathen deity or god, called Jupiter Ammon. These shells, at once the wonder and pride of geologists, are found in the chalk formations, and thousands of years must have passed away since they were inhabited by living creatures. The Nautili which swam and sported with them at the depths of the ocean, as is proved by the shells of many species found in the same chalky deposits, have still their living representatives, but those winding galleries and pearly chambers once fragile as paper and brittle as glass, now turned into, and surrounded by solid stone, are all shells of extinct species, and we can hardly see and handle them without some degree of awe and reverence; when we reflect on the great and wonderful changes that have passed over the earth since they were formed by a hand divine, instinct with the breath of life, and then to be embedded in the rock as everlasting characters by which the unborn generations of men might read in history of those changes, and of the providential dealings of God with his creatures. Of these Ammonites, and other fossil shells, much more will have to be said in our proposed geological volume; the poem which follows will very appropriately conclude the above remarks, and our present little work on shells—beautiful, wonderful shells! useful, ornamental, instructive! The subject is one which we would earnestly invite our young readers to study: it is but here introduced; we have picked up a few, very few, of the wonders and beauties of conchology, and presented them to their notice in the hope that they may be induced to desire a more intimate acquaintance with this branch of natural science, which has been hitherto greatly neglected. To understand it thoroughly, much attention and perseverance will be required, but even a slight acquaintance with it will yield both pleasure and profit to the mind.

THE NAUTILUS AND THE AMMONITE.

The Nautilus and the Ammonite,
Were launched in storm and strife;
Each sent to float in its tiny boat,
On the wide, wild sea of life.

And each could swim on the ocean’s brim,
And anon its sails could furl,
And sink to sleep in the great sea deep,
In a palace all of pearl.

And their’s was a bliss more fair than this,
That we feel in our colder time;
For they were rife in a tropic life,
In a brighter, happier clime.

They swam ’mid isles whose summer smiles
No wintry winds annoy;
Whose groves were palm, whose air was balm,
Whose life was only joy.

They roam’d all day through creek and bay,
And travers’d the ocean deep;
And at night they sank on a coral bank,
In its fairy bowers to sleep.

And the monsters vast of ages past,
They beheld in their ocean caves;
And saw them ride in their power and pride,
And sink in their billowy graves.

Thus hand in hand, from strand to strand,
They sail’d in mirth and glee;
Those fairy shells, with their crystal cells,
Twin creatures of the sea.

But they came at last to a sea long past,
And as they reach’d its shore,
The Almighty’s breath spake out in death,
And the Ammonite liv’d no more.

And the Nautilus now in its shelly prow,
As o’er the deep it strays,
Still seems to seek in bay and creek,
Its companion of other days.

And thus do we, in life’s stormy sea,
As we roam from shore to shore;
While tempest-tost, seek the lov’d—the lost,
But find them on earth no more!

G. F. RICHARDSON.

INDEX.

PAGE.