The Sea and Its Living Wonders / A Popular Account of the Marvels of the Deep and of the Progress of Martime Discovery from the Earliest Ages to the Present Time

While the fishing goes on, a number of conjurors and priests are assembled on the coast, busily employed in protecting the divers by their incantations against the voracity of the sharks. These are the great terror of the divers, but they have such confidence in the skill or power of their conjurors that they neglect every other means of defence. The divers are paid in money, or receive a part of the oyster-shells in payment. Often, indeed, they try to add to their gains by swallowing here or there a pearl, but the sly merchant knows how to find the stolen property. The oysters, when safely landed, are piled up on mats, in places fenced round for the purpose. As soon as the animals are dead, the pearls can easily be sought for and extracted from the gaping shells. After the harvest has been gathered, the largest, thickest, and finest shells, which furnish mother-of-pearl, are sorted, and the remaining heap is left to pollute the air. Some poor Indians, however, often remain for weeks on the spot, stirring the putrid mass in the hopes of gleaning some forgotten pearls from the heap of rottenness. The pearls are drilled and stringed in Ceylon, a work which is performed with admirable dexterity and quickness. For cleaning, rounding, and polishing them, a powder of ground pearls is made use of.

The Pacific also furnishes these costly ornaments to wealth and beauty, but the pearls of California and Tahiti are less prized than those of the Indian Ocean.

Pearl-like excrescences likewise form on the inner surface of our oysters and mussels, and originate in the same manner as the true pearls. The formation of the pearl, however, is not yet quite satisfactorily accounted for. Some naturalists believe that the animal accumulates the pearl-like substance to give the shell a greater thickness and solidity in the places where it has been perforated by some annelide or gasteropod; and according to Mr. Philippi, an intestinal worm stimulates the exudation of the pearl-like mass, which, on hardening, encloses and renders it harmless.

Brilliancy, size, and perfect regularity of form are the essential qualities of a beautiful pearl. Their union in a single specimen is rare, but it is of course still more difficult to find a number of pearls of equal size and beauty for a costly necklace or a princely tiara.

Nature has given the bivalves the same beauty of colouring and wonderful variety of elegant or capricious forms as to the sea-snails; so that they are equally esteemed in the cabinets of wealthy amateurs. Among the most costly are reckoned the Spondyli, which are found in the tropical seas, where they grow attached to rocks. They are distinguished by the brilliancy of their colours, but particularly by the long thorny excrescences with which their shells are covered. A Parisian professor once pawned all his silver spoons and forks to make up the sum of six thousand francs which was asked for a Royal Spondylus; but on returning home was so warmly received by his lady that, overwhelmed by the hurricane, he flung himself on a chair, when the terrific cracking of the box containing his treasure reminded him too late that he had concealed it in his skirt-pocket. Fortunately but two of the thorns had been broken off, and the damage was susceptible of being repaired; his despair, however, was so great that his wife had not the heart to continue her reproaches, and in her turn began to soothe the unfortunate collector.

The gigantic Tridacna, which is now to be found in the shop of every dealer in shells, was formerly an object of such rarity and value that the Republic of Venice once made a present of one of them to Francis I., who gave it to the Church of St. Sulpice in Paris, where it is still made use of as a basin for holy water. The tridacna attains a diameter of five feet, and a weight of five hundred pounds, the flesh alone weighing thirty. The muscular power is said to be so great as to be able to cut through a thick rope on closing the shell. It is found in the dead rocks on the coral reefs, where there are no growing lithophytes except small tufts. Generally only an inch or two in breadth of the ponderous shell is exposed to view, for the tridacna, like the pholas, has the power of sinking itself in the rock, by removing the lime about it. Without some means like this of security, its habitation would inevitably be destroyed by the roaring breakers. A tuft of byssus, however strong, would be a very imperfect security against the force of the sea for shells weighing from one to five hundred pounds. It is found in the Indian Ocean and the Pacific as far as the coral zone extends. The animal of the tridacna, and of the nearly related Hippopus, distinguishes itself by the beauty of its colours. The mantle of the Tridacna safranea, for instance, has a dark blue edge with emerald-green spots, gradually passing into a light violet. When a large number of these beautiful creatures expand the velvet brilliancy of their costly robes in the transparent waters, no flower-bed on earth can equal them in splendour.

Like the Lamellibranchiate Acephala, the Brachiopods are covered with a bivalve shell, but their internal organisation is very different. Instead of being disposed in separate gills, their respiratory system is combined with the ciliated mantle on which the vascular ramifications are distributed, but their most striking feature is the possession of spiral fringed arms or buccal appendages which serve to open the shell and occupy the greater part of its cavity. These curious organs are in some Brachiopods quite free, in others attached to a complicated cartilaginous or calcareous skeleton. None of the existing molluscs of this class are capable of changing place, but are either fixed to extraneous substances by the agglutination of one of their valves or by a muscular peduncle passing through a perforation of their shells. There are no more than forty-nine living species, chiefly belonging to the genera Terebratula and Crania, and generally found at great depths in the Southern Ocean; but the fossil remains of 1,370 species prove their importance in the primitive seas, where they rivalled the lamellibranchiates in numbers and variety. Though now so rare or so local in the British seas that ordinary collectors are not likely to meet with any, they abound in many of our oldest rocks. "A visit to the quarries at Dudley," says E. Forbes, "or an Irish lime-kiln, or an oolitic section on the Dorsetshire coast, or a green sand ravine in the Isle of Wight, will afford more information about the Brachiopods than an examination of the finest collection of the living species. In each of the above excursions a different set of forms would be collected, for many of the palæozoic genera have altogether disappeared when we rise among the secondary rocks, and in the latter we find forms which closely remind us of existing species, but which, though very near, are yet unquestionably distinct. In formations of all epochs, a few generic types are common, and the Lingulæ of the earliest sedimentary formations, presenting traces of organic life, strikingly remind us of the species of that curious group living in exotic seas at the present day."

At the lower extremity of the great series of molluscous animals we find the Polyzoa (Bryozoa, or Sea-Mosses) and Tunicata. The former, which comprise the Sea-Mats (Flustræ, Escharæ), the Sea-Scurfs (Lepraliæ), the Retepores, the Cellulariæ, and several other families, were formerly reckoned among the polyps, whom they greatly resemble in appearance and mode of life, but far surpass by the complexity of their internal organisation. The Sea-Mats are among the commonest objects which the tide casts out upon our shores, for you will hardly ever walk upon the strand without finding their blanched skeletons among the relics of the retiring flood. Their flat leaf-like forms might easily cause them to be mistaken for dried sea-weeds, but a pocket-lens suffices to show that they are built up of innumerable little oblong cells, placed back to back like those of a honey-comb, and each crowned by four stout spines, which give their surface a peculiarly harsh feel when the finger is passed over it from the apex to the base. "The individual cells," says Mr. Gosse, "are shaped like a child's cradle, and if you will please to suppose some twenty thousand cradles stuck side to side in one plane, and then turned over, and twenty thousand more stuck on to these bottom to bottom, you will have an idea of the framework of a flustra. And do not think the number outrageous, for it is but an ordinary average. I count in an area of half an inch square sixty longitudinal rows, each of which contains about twenty-eight cells in that space; this gives 6,720 cells per square inch on each surface. Now a moderate-sized polyzoary contains an area of three square inches, i. e. six on both surfaces, which will give the high number of 40,320 cells on such a specimen. Many, however, are much larger."

Before the stormy tide detached them from the bottom of the sea, and left them to perish on the shore, each of the cells contained a living creature whose mouth was surrounded by a coronet of filiform and ciliated tentacles, destined to produce a vortex in the water, and thus to provide the tiny owner with its food. The body was bent on itself somewhat like the letter V, the one branch (a) being the mouth and throat, the other (b) the rectum, opening by an anus, and the middle part (c) the stomach. Each of these tiny members of the flustra colony possessed a considerable number of muscles; each was furnished with a movable lip or lid to block up the entrance of his cell when he courted retirement; each had his individual nerves, and consequently his individual sensations, though feeling and moving simultaneously with his fellow citizens by the agency of a system of nerves common to the whole republic, and sending forth a delicate filament to the inmate of each cell.

Such are the wonders which but for the microscope would for ever have remained unknown to man.

The Escharæ greatly resemble the Flustræ, for here also the cells are disposed side by side upon the same plane, so as to form a broad leaf-like polyzoary, which, however, is not of a horny or coriaceous texture, as in the latter genus, but completely calcified, so as to present something of the massiveness of the stony corals. The annexed wood-cuts, showing us Eschara cervicornis, first A, in its natural size; then B, a few cells magnified twenty diameters, and ultimately C, a single individual so highly magnified as to reveal some of the details of its otherwise invisible structure, give us a good idea of the truly remarkable organisation of the Polyzoa.

In the Escharæ and Flustræ the cellular extension of the common stock or polyzoary is unbroken, and opening on both surfaces, while in the Retepores we find the cells opening only on one side, and the leaf-like expansion pierced like network.

In cabinets of natural history, the species commonly called Neptune's ruffles will rarely be found wanting. It is a native of the Mediterranean, but individuals of a smaller size are also found in the British seas.

The Lepraliæ, or Sea-Scurfs, form thin calcareous crusts of a white-yellow or reddish colour on rocks, shells, and sea-weeds. To the naked eye they appear as rude unsightly eruptions, so as to justify their name derived from the hideous leprosy of the East, but, when magnified, their cells, generally disposed in regular concentric rows, exhibit a surprising diversity and elegance of structure. Forty species are found in the North Sea alone; hence we may judge how great the number of still unknown forms must be that spread their microscopic traceries over the algæ and shells of every zone.

It would lead me too far were I minutely to describe the Cellulariæ with their cells disposed in alternating rows on narrow bifurcated branches; the Tubulipores, with their mouths at the termination of tubular cells without any movable appendage or lip; the Bowerbankias and Lagunculas, with their creeping stems and separate cells; suffice it to say that a wonderful exuberance of fancy displays itself in the structure of the numerous varieties of the Polyzoa.

But a closer inspection reveals still greater miracles to the marine microscopist, for most genera, and chiefly the Cellulariæ, possess very remarkable appendages, or processes, presenting the most striking resemblance to the head of a bird. Each of these processes, or "aviculariæ," as they have been named, has two "mandibles," of which one is fixed like the upper jaw of a bird, the other movable like its lower jaw; the latter is opened and closed by two sets of muscles, which are seen in the interior of the head, and between them is a peculiar body, furnished with a pencil of bristles, which is probably a tactile organ, being brought forwards when the mouth is open, so that the bristles project beyond it, and being drawn back when the mandible closes. During the life of the polyzoon, these tiny "vulture-heads," which are either sessile or pedunculated, keep up a continual motion, and it is most amusing to see them see-sawing and snapping and opening their jaws, and then sometimes in their incessant activity even closing upon the beaks of their neighbours.

It is still very doubtful what is their precise function in the economy of the animal; whether it is to retain within reach of the ciliary current bodies that may serve as food, or whether it is like the pedicellariæ of the sea-urchins to remove extraneous particles that may be in contact with the surface of the polyzoary. The latter would seem to be the function of the "vibracula," which are likewise pretty generally distributed among the polyzoa. Each of these long bristle-shaped organs, springing at its base out of a sort of cup, that contains muscles by which it is kept in almost constant motion, sweeps slowly and carefully over the surface of the polyzoary, and removes what might be injurious to the delicate inhabitants of the cells, when their tentacles are protruded. So carefully have these lowly molluscs been provided for!

The polyzoa can neither hear nor see, at least as far as we are able to ascertain, but the delicacy of their sense of touch is very great. "When left undisturbed in a glass of fresh sea-water," says Dr. Johnston,[R] "they push their tentacula beyond the mouth of the cell by straightening the body, and then expanding them in the form of a funnel or bell, they will often remain quiet and apparently immovable for a long time, presenting a very pretty and most interesting object to an observer of the 'minims of nature.' If, however, the water is agitated, they withdraw on the instant, probably by aid of the posterior ligament or muscle; the hinder part of the body is pushed aside up the cell, the whole is sunk deeper, and by this means the tentacula, gathered into a close column, are brought within the cell, the aperture of which is shut by the same series of actions. The polyzoa of the same polyzoary often protrude their thousand heads at the same time, or in quick but irregular succession, and retire simultaneously, or nearly so, but at other times I have often witnessed a few only to venture on the display of their glories, the rest remaining concealed, and if, when many are expanded, one is singled out and touched with a sharp instrument, it alone feels the injury, and retires, without any others being conscious of the danger, or of the hurt inflicted on their mate. The polyzoa propagate by gemmation and by ova or eggs, which, germinating on the inner surface, escape at a later period into the visceral cavity, and are finally discharged into the wide sea, so to fulfil their mission in creation, and people the shores of every clime with myriads of busy workers in horn and in lime, which, with subtle chemistry, they draw from a fluid quarry and build up in textures of admirable beauty and heaven-ordered designs."

Each polyzoon begins with a single ovum. The original or seminal cell of a flustra or lepralia has no sooner fixed itself upon some stone, shell, or alga, than new buds begin to shoot forth, which in their turn produce others from their unattached margins, so as rapidly to augment the number of cells to a very large amount. Thus a common specimen of Flustra carbasea presents more than 18,000 individual polyzoa, and as each of these has about twenty-two tentacula, which are again furnished with about a hundred ciliæ a piece, the entire polyzoary presents no less than 396,000 tentacula and 39,600,000 ciliæ. The Rev. David Landsborough calculated that a specimen of Flustra membranacea five feet in length by eight inches in breadth had been the work and the habitation of above two millions of inmates, so that this single colony on a submarine island was about equal in number to the population of Scotland. As the tentacula are numerous in this species, four thousand millions of ciliæ must have provided for its wants, about four times the number of the inhabitants of this globe!

The Tunicata are so called because their soft parts are not enclosed in a calcified shell such as invests the majority of their class, but in a more or less coriaceous envelope or tunic which is either bag-shaped, and provided with two apertures, or tube-shaped, and open at the ends. They present a strong resemblance to the Polyzoa, not merely in their general plan of conformation, but also in their tendency to produce composite structures by gemmation; they may, however, be at once distinguished from them by the absence of the ciliated tentacula which form so conspicuous a feature in the external aspect of a flustra or a retepore. Their branchiæ, which have generally the form of ridges (e), occupy a large sac, forming, as it were, the antechamber of the alimentary canal, which is barely distinguishable into gullet, stomach, and intestine, and always convoluted or folded once on itself. The Tunicata are exclusively marine, and widely spread from the arctic to the tropical seas. All of them are free during the earlier parts of their existence; some remain permanently so (Pyrosomidæ, Salpæ), but the generality (Ascidiæ, Botrylli) become fixed to shells and other marine bodies; some exist as distinct individuals (Ascidiæ, Cynthia), whilst various degrees of combination are effected by others (Botryllus, Clavellina, Pyrosoma), and some are simple in one generation and combined in the next (Salpæ).

Thus the whole family is divisible into two groups, the simple and the aggregate; both branching out into numerous genera, of which my limits only allow me to mention some of the most remarkable. The simple Ascidiæ, or Sea-Squirts, are very common on our shores. "Rarely," says Forbes, "is the dredge drawn up from any sea-bed at all prolific in submarine creatures without containing few or many of their irregularly shaped leathery bodies, fixed to sea-weed, rock, or shell, by one extremity, or by one side, free at the other, and presenting two more or less prominent orifices, from which, on the slightest pressure, the sea-water is ejected with great force. On the sea-shore, when the tide is out, we find similar bodies attached to the under surface of rough stones. They are variously, often splendidly, coloured, but otherwise are unattractive or even repulsive in aspect. Some are of a large size, several inches in length. As may easily be imagined, they lead a very inactive life, except in the young state, when by means of a long tail they rapidly swim about, until finally settling in some convenient spot, they gradually assume the form and adopt the quiet life of the parent from which they sprang."

To the simple Tunicata belong also the Chelyosomata, whose coriaceous envelope, consisting of eight somewhat horny angular plates, reminds one of the carapace of the turtle. Their small and prominent orifices, perforating the plated surface, are each surrounded by six triangular valvules.

Some species of simple Ascidians on the coasts of the Channel and the Mediterranean are valued as articles of food. At Cette sea-squirts are taken regularly to market, and Cynthia microcosmus, although so repulsive externally, furnishes a very delicate morsel.

While in the Clavellinidæ the animals are connected by creeping tubular prolongations of the common tunic through which the blood circulates, the Botrylli form translucent jelly-like masses of various hues of orange, yellow, purple, blue, grey, and green; sometimes nearly uniform in tint, sometimes beautifully variegated, and very frequently pencilled as if with stars of gorgeous device; now encrusting the surface of the rock, now descending from it in icicle-like projections. They are also frequently attached to the broad-leaved fuci, investing the stalks, or clothing with a glairy coat the expanse of the fronds. "In examining their bodies," says the distinguished naturalist previously quoted, "we find that it is not a single animal which is before us, but a commonwealth of beings bound together by common and vital ties. Each star is a family, each group of stars a community. Individuals are linked together in systems, systems combined into masses. Few bodies among the forms of animal life exhibit such exquisite figures as those which we see displayed in the combinations of these compound Ascidians."

In the genus Diazona, which has its chief seat in the Mediterranean, the animals, which are very prominent and arranged in concentric circles, form a single system expanded into a disc like that of a flower or of an Actinia. The anal orifices, it will be seen, are situated close to the branchial apertures at the free end of the single animals, while in the Botrylli they open into a central excretory cavity.

In the Pyrosomes we find large colonies of small individuals aggregated in the form of a cylinder open at one end. Their mouths or anterior extremities are situated on the exterior of this hollow body, which they bristle with large and longish tubercles (a), whilst the opposite or anal orifices (b) open into the cavity of the cylinder, whose smooth wall they perforate with numerous small holes. By a simultaneous action the central cavity is either narrowed or enlarged, and by this means the strange social republic glides slowly through the waters.

The Pyrosomes inhabit the Mediterranean and the warmer parts of the ocean. In the former at times their abundance is a source of great annoyance to the fishermen, sometimes even completely clogging their nets, and on the high seas they are not seldom met with in almost incredible profusion. Their delicate and transparent forms, their elegant tints, and their unrivalled phosphorescence render them objects of admiration to the voyager, and entitle them to rank amongst the most resplendent living gems of the ocean.

While the sessile Ascidiæ remind one of the polyps, the transparent Salpæ, freely swimming in the sea, bear a great resemblance to the pellucid jelly-fishes. Each resembles a crystalline tube, through which one can distinctly see the internal coloured parts. Sometimes these animals, which abound in the warmer seas, are found solitary, at other times associated in circular or lengthened groups, termed garlands, ribands, and chains; but, strange to say, these two forms so different in outward appearance are only the alternating generations of one and the same animal. The chained Salpæ produce only solitary ones, and the latter only chains, or, as Chamisso, to whom we owe the discovery of this interesting fact, expresses himself, "a salpa mother never resembles her daughter, or her own mother, but is always like her sister, her grand-daughter, or her grand-mother." When Chamisso first made known his discovery, he was laughed at as a fanciful visionary, but all later observations have not only fully confirmed his statement but also discovered similar or even more wonderful metamorphoses among the jelly-fish, polyps, crustacea, sea-urchins, and other marine animals. Thus Chamisso gave the first impulse to a whole series of highly interesting observations, and his rank is now as well established among naturalists as it has long been among the most distinguished poets of Germany. The Salpæ progress by the alternate contractions and dilatations of their tubular body. In this manner the chains, as if obeying a common impulse, glide along with a serpentine movement, and are often regarded by sailors as sea-snakes.

Before quitting the Tunicata, a few points of interest in their simple history remain to be noticed. Despite their humble organisation, they have a heart which, as may easily be ascertained in the transparent species, is subject to strange alternations of action. For after having received for a minute or two the blood from the branchiæ, and propelled it to the system at large, it will at once cease to pulsate for a moment or two, and then propel the blood to the branchial sac, receiving it at the same time from the system generally. After this reversed course has continued for some time, another pause occurs, and the first course is resumed. It is very probable that many of the Tunicata are able to hear and to see. In Chelyosoma, organs have been discovered whose structure seems to indicate that they are destined for the transmission of sound, and the Ascidiæ have frequently around the extremity of their tubes a row of coloured points similar to the imperfect organs of sight present in the majority of the bivalve Acephalans. Thus a closer examination of the lower animals is constantly bringing new faculties to light, and the further we penetrate into the secrets of their life the more we find occasion to admire the power and wisdom of their Maker!

CHAP. XVI.

ECHINODERMATA.

STAR-FISHES, SEA-URCHINS, AND SEA-CUCUMBERS.

"As there are stars in the sky, so are there stars in the sea," is the poetical exordium of Link's treatise on Star-fishes, the first ever published on the subject; and James Montgomery tells us in rather bombastic style, that the seas are strewn with the images of the constellations with which the heavens are thronged.

This is no doubt highly complimentary to the star-fishes, but is far from being merited by any particularly shining or radiant quality; as they occupy a very inferior grade among the denizens of the sea, and merely owe their stellar name to their form, which somewhat resembles the popular notion of a star.

But if they are of an inferior rank to most marine animals; if even the stupid oyster boasts of a heart, which they do not possess; yet a closer inspection of their organisation shows us many wonderful peculiarities, and proves to us once more that nature has impressed the stamp of perfection as well upon her lowest and most simple creations, as upon those beings that rank highest in the scale of life.

Every one knows the common Star-fish, with its lanceolate arms; its generally orange-coloured back, thickly set with tubercles, and the pale under-surface, with its rows of feet, feelers, or suckers, which serve both for locomotion and the seizure of food.

When one of these creatures is placed on its back, in a plate filled with sea-water, it is exceedingly curious to watch the activity which those numberless sucking feet display. At first the star-fish is motionless; for, offended by the rough handling it has undergone, the feet have all shrunk into the body; but soon they are seen to emerge like so many little worms from their holes, and to grope backwards and forwards through the water, evidently seeking the nearest ground to lay hold of. Those that reach it first immediately affix their suckers, and, by contracting, draw a portion of the body after them, so as to enable others to attach themselves, until, pulley being added to pulley, their united power is sufficient to restore the star-fish to its natural position.

The upper tuberculated surface is shown, with some of the spines of the under surface projecting at the sides of the rays. At one of the angles between the rays, on the right side, is seen the eccentric calcareous plate, or madreporic tubercle, which indicates the existence of a bilateral symmetry.

This act of volition is surely remarkable enough in so simple an animal, which scarcely possesses the rudiments of a nervous system, but the simple mechanism by which the suckers are put into motion is still more wonderful. Each of these little organs is tubular, and connected with a globular vesicle filled with an aqueous fluid, and contained within the body of the star-fish immediately beneath the hole from which the sucker issues. When the animal wishes to protrude its feet, each vesicle forcibly contracts, and, propelling the fluid into the corresponding sucker, causes its extension; and, when it desires to withdraw them, a contraction of the suckers drives back the fluid into the expanding vesicles. The internal walls of the suckers and their vessels are furnished with vibratory cilia, and by this simple means a continual circulation of the fluid they contain goes on within them.

Numerous species of star-fishes are so very common in our waters, that in many places the sea-bottom is literally paved with them. They likewise abounded in the primeval ocean, for deep beds of carboniferous limestone and vast strata of the triassic muschelkalk are often formed by the accumulation of little else than the skeletons of Encrinites and Pentacrinites, which, unlike the sea-stars which every storm drifts upon our shores, did not move about freely, but were affixed to a slender flexible stalk, composed of numerous calcareous joints connected together by a fleshy coat. The feathered bifurcated arms of the Crinoids are unprovided with suckers, which would have been perfectly useless to creatures not destined to pursue their game to any distance, but passively to receive the nutriment which the current of sea-water set in motion by their richly-ciliated pinnules conveys to the mouth. These beautiful creatures were formerly supposed to be nearly extinct, for up to within the last few years only two living stalked crinoids were known in the ocean of the present period, but the dredge has latterly brought up new and remarkably fine species from depths of more than 2000 fathoms, and there is every reason to believe that these animals still form an important element in the abyssal fauna.[S]

Of freely-swimming Crinoids but one single representative is known in the northern seas, the Rosy Feather-star (Comatula rosacea), whose long and delicately fringed rays and deep rose colour dotted with brown may serve to give us an idea of the beauty of the submarine landscapes where Pentacrinus Wyville-Thomsoni or Bathycrinus gracilis abound. During the earlier stage of its existence, the comatula is attached to a stalk; a discovery for which science is indebted to Mr. T. V. Thompson, who in 1823 dredged in the Cove of Cork a singular little pedunculated crinoid animal (Pentacrinus europæus), which he found attached to the stems of zoophytes. It measured about three-fourths of an inch in height, and resembled a minute comatula mounted on the stalk of a pentacrinus. When this pygmy representative of the ancient lily-stars was first dragged up from its submarine haunts, it created a great sensation among naturalists, as it was the first recent animal of the encrinite kind which had ever been seen in the seas of Europe. At first it was supposed to be a distinct species, but Mr. Thompson, by carefully following it through all the stages of its growth, succeeded in proving that it was merely the hitherto unnoticed young of the rosy feather-star.

This elegant crinoid is found all round our coasts, and its range extends from Norway to the shores of the Mediterranean. In swimming, the movements of its arms exactly resemble the alternating stroke given by the medusa to the liquid element, and have the same effect, causing the animal to raise itself from the bottom and to advance back foremost, even more rapidly than the medusa. When dying, either in fresh water or in spirits, it emits a most beautiful purple colour, which tinges the liquid in which it is killed.

The Ophiuridæ, or snake-stars, are essentially distinguished from the true star-fishes by the long serpent or worm-like arms, which are appended to their round, depressed, urchin-like bodies. They have no true suckers with which to walk, their progression being effected (and with great facility) by the twisting or wriggling of their arms, which are moreover in many species furnished with spines on the sides, assisting locomotion over a flat surface. These arms are very different from those of the true star-fishes, which are lobes of the animal's body, whereas the arms of the Ophiuridæ are mere processes attached or superadded to the body.

These animals are very generally distributed through the seas of our earth, both of its northern and southern hemispheres, but are found largest in the tropical ocean. In our own waters they are very abundant, and are among the most curious and beautiful game pursued by the dredger.

The British Ophiuridæ belong to two generic types, that of the Ophiuræ and that of the Euryales. The former, to which the sand and brittle-stars belong, have simple arms; the latter, arms ramifying into many processes.

The rays of the Sand-stars have a whip-like or lizard-tail appearance, while those of the Brittle-stars look like so many centipedes or annelides attached at regular distances round a little sea-urchin. We have ten native brittle-stars, the most common of which (Ophiocoma rosula, Forbes) is also one of the handsomest, presenting every variety of variegation, and the most splendid displays of vivid hues arranged in beautiful patterns. Not often are two specimens found coloured alike. It is the most brittle of all brittle-stars, separating itself into pieces with wonderful quickness and ease. Touch it, and it flings away an arm; hold it, and in a moment not an arm remains attached to the body. "The common brittle-star," says Edward Forbes, "often congregates in great numbers on the edges of scallop-banks, and I have seen a large dredge come up completely filled with them; a most curious sight, for when the dredge was emptied, these little creatures, writhing with the strangest contortions, crept about in all directions, often flinging their arms in broken pieces around them; and their snake-like and threatening attitudes were by no means relished by the boatmen, who anxiously asked permission to shovel them overboard, superstitiously remarking that the things weren't altogether right."

Fancy the naturalist's vexation, who has no other means of preserving a brittle-star entire than by quickly plunging it into cold fresh water, which acts as a poison on the Ophiuræ as well as on most other marine animals, and kills them so instantaneously that even the most brittle species have no time to make the contraction necessary to break off their rays.

The Ophiocoma rosula seems to be equally abundant on all parts of the coast of Britain and Ireland. It is fond of rocky places, and grows in Shetland to a much larger size than elsewhere. It is said to prey on little shells and crabs, and is greatly relished by the cod in its turn, great numbers being often found in the stomach of that voracious fish.

The Scotch or Shetland Argus (Euryale verrucosum, Lamarck), a very rare animal, of which the adjoining wood-cut represents a segment, is the only British Euryale. It measures a foot or more across, and its singular aspect has long excited admiration among naturalists. "So odd a creature as this," remarks Bradley in his "Works of Nature," "is well worth the contemplation of such curious persons as live near the sea, where every day they have subjects enow to employ their curiosity and improve their understanding." Grew says that "as he swims he spreads and stretches out all his branches to their full length, and so soon as he perceives his prey within his reach, he hooks them all in, and so takes it as it were in a net."

The British species of true star-fishes may be arranged under four families. The Urasters are distinguished from all others by having four rows of suckers in each of the avenues which groove the under surface of their rounded rays. In consequence of the great number of these singular organs, the under surface of a living cross-fish presents a sight truly curious and wonderful. Hundreds of worm-like suckers, extending and contracting, coiling and feeling about, each apparently acting independently of the others, give the idea rather of an assemblage of polypi than of essential parts of one animal. They are sensitive in the extreme, for, if we touch one of those singular tubes when outstretched, all those in its neighbourhood are thrown into a state of agitation; and when it shrinks from our touch, changing from a lengthy fibre to a little shrunk tubercle, some of its neighbours, as if partaking in its fears, contract themselves in like manner.

The common Cross-fish (Uraster rubens) abounds on most parts of our shores, so as in some places to be used for manure in large quantities. "It is a sworn enemy to oysters, and as it is frequently found with one or more of its rays broken off, the fishermen fancy that it loses them in consequence of its oyster-hunting propensities; that it insinuates an arm into the incautious oyster's gape, with the intent of whipping out its prey, but that sometimes the apathetic mollusk proves more than a match for its radiate enemy, and closing on him, holds him fast by the proffered finger; whereupon the cross-fish preferring amputation and freedom to captivity and dying of an oyster, like some defeated warrior flings his arms away, glad to purchase the safety of the remaining whole by the reparable loss of a part, as it has the power of reproducing the broken rays.

"There is, however, reason to think that the cross-fish destroys his prey in a very different manner from that just narrated; for star-fishes are not unfrequently found feeding on shell-fish, enfolding their prey within their arms, and seeming to suck it out of its shell with their mouths, pouting out the lobes of the stomach, which they are able to project in the manner of a proboscis. Possibly the stomach secretes an acrid and poisonous fluid, which, by paralysing the shell-fish, opens the way to its soft and fleshy parts."—Forbes's Star Fishes.

The Solasters are "suns in the system of sea-stars," and are entitled to this distinguished rank among the marine constellations by their many rays and brilliant hues. The Solaster papposa, or common Sun-star, with rays varying in number from twelve to fifteen, is one of the commonest, and at the same time handsomest, of all the British species. Sometimes the whole upper surface is deep purple, and frequently the disk is red, and the rays white tipped with red. It grows to a considerable size, having been found eleven inches broad.

The Goniasters, or Cushion-stars, are distinguished from the allied species by their pentagonal form. One of the most singular of our native species is the Birdsfoot Sea-star (Palmipes membranaceus), being the thinnest and flattest of all its class. When alive it is flexible, like a piece of leather, and a person who had never seen it before would be apt to mistake it for the torn off dorsal integument of some gibbous goniaster. The colour is white, with a red centre and five red rays, proceeding one to each angle. The whole upper surface is covered with tufts of minute spines arranged in rows.

The Asteriæ, with their stellate body and flat rays, are very different in aspect from the Goniasters. The Butt-thorn (Asterias aurantiaca) owes its name to one of those strange superstitions which originate in some inexplicable manner, and are handed down by one credulous generation to the next. "The first taken by the fishermen at Scarborough is carefully made a prisoner, and placed on a seat at the stern of the boat. When they hook a butt (halibut) they immediately give the poor star-fish its liberty and commit it to its native element; but if their fishery is unsuccessful it is left to perish, and may eventually enrich the cabinet of some industrious collector."

To the family of the Asteriæ belongs also the Ling-thorn (Luidia fragilissima), the largest, and one of the most interesting of our British species. When full grown, it measures two feet across, and would appear to exceed that size occasionally, judging from fragments. The rays are from five to seven in number, quite flat, and generally five times as long as the disk is broad. The colour is brick-red above, varying in intensity, the under surface being straw-coloured. The wonderful power which the Luidia possesses, not merely of casting away its arms entire, but of breaking them voluntarily into little pieces with great rapidity, approximates it to the brittle-stars, and renders the preservation of a perfect specimen a very difficult matter.

"The first time I ever took one of these creatures," says Edward Forbes, "I succeeded in getting it into the boat entire. Never having seen one before, and quite unconscious of its suicidal powers, I spread it out on a rowing-bench, the better to admire its form and colours. On attempting to move it for preservation, to my horror and disappointment I found only an assemblage of rejected members. My conservative endeavours were all neutralised by its destructive exertions, and it is now badly represented in my cabinet by an armless disk and a diskless arm. Next time I went to dredge on the same spot, determined not to be cheated out of a specimen in such a way a second time, I brought with me a bucket of cold fresh water, to which article star-fishes have a great antipathy. As I expected, a luidia came up in the dredge, a most gorgeous specimen. As it does not generally break up before it is raised above the surface of the sea, cautiously and anxiously I sunk my bucket to a level with the dredge's mouth, and proceeded in the most gentle manner to introduce luidia to the purer element. Whether the cold air was too much for him, or the sight of the bucket too terrific, I know not, but in a moment he proceeded to dissolve his corporation, and at every mesh of the dredge his fragments were seen escaping. In despair I grasped at the largest, and brought up the extremity of an arm with its terminating eye, the spinous eyelid of which opened and closed with something exceedingly like a wink of derision."