name will at once suggest the peculiar structure of the crab; others may feel inclined to regard it as pedantic. But as the meaning of the designation is simply this, that the crab is a crustacean with a short tail and ten feet, it is an exact description of the animal. Our notices must be limited to a few only of the more remarkable species, their singular habits and peculiar structure. The spider-crabs, so named from the great length of their legs, are found on many parts of the south, west, and east coasts of England. The large reddish, spine-backed spider-crab of Cornwall (Maia squinado) has sometimes the front legs fifteen inches long. Though little prized as food, and contemptuously

these fights, claws, limbs, and shells are torn, wrenched, and cracked, with a fury and energy to which a battle between two game-cocks is but play. When a large crab has seized a smaller, he tears open the shell, and scoops out the flesh of his living captive. Perhaps, while the conqueror is enjoying his feast, a still stronger crab will tear open the body of the victor, and feed upon him. The most singular fact is, that a crab, while thus being eaten, will actually continue to feed on the victim seized by himself. Here appears a total insensibility to suffering. A crab has been known to lose seven of its limbs in a fight, and immediately after to begin eating a captured mollusk, as if nothing particular had happened. These furious battles are probably

called "spiders" by the fishermen, this crustacean was highly honoured by the ancient Greeks, who deemed it a "rational animal," used it as a symbol of wisdom, and sculptured it on the statue of "Diana of the Ephesians." Still more was this genus honoured by receiving the name Maia, that of the mother of Mercury; and it is probable that the month of May was named from the same root. Thus the spine-backed spider-crab is not without a history.

The common edible crabs of the fish-shops (Cancer pagurus), though well known, require some notice. They are found on rocky parts of our coasts, the small animals inhabiting holes in the cliffs, but the larger and more experienced dwelling in deeper waters. When caught and kept alone in an aquarium, one of these crabs may become tame and quite familiar; but if placed with others of its race, a series of desperate battles will soon declare the degree to which the ferocity of the crab may extend. In

not so common when the crabs are in their natural state, as when pent up in a close marine tank.

The small red crab (Carcinus manas) sold by the London costermongers is, of course, to be classed with the edible kind, though grouped with the portunians, or paddling crabs. It is easily found a little beneath the sand when the tide has gone down. One may be kept for several days in moist sand only; and if the captor will give his crab a mussel, he will receive his reward by observing the grave earnestness with which the crustacean scoops out the flesh with its handlike claws. This crab is of a greenish tint when alive; the red colour of those on the stalls arises from the oxidation of the shell when boiled.

The voracity of the common crab renders it an easy prey to the fisherman, who has only to bait his wicker traps, called "crab-pots," or "stalkers," with useless or decayed fish, and

sink them in a suitable place, when the eager crustaceans will soon enter. Readers have, doubtless, noticed in the shops huge specimens of the edible crab; these fellows, brought up from deep waters, have sometimes weighed twelve pounds each. Perhaps the most remarkable of our British crustaceans is the hermit crab (Pagurus Bernhardus). There is no mistaking this red and yellow tinted crab, as he runs along the sand, dragging with him the whelk or other shell which he has appropriated for his house. Most readers are aware that this family of crabs is without any shell on the hinder part of the body. Were this all, we might simply note the fact as a remarkable deviation from the usual structure of crustaceans. We should also infer that the animal's habits were suited to its peculiar formation, and that no sense of a deficiency in its covering would be felt by the creature. But this is not so; the crab does feel the absence of its protection, and remedies the want by seizing on the shells of other animals, and inserting the unde

When the hermit grows too large for the shell first appropriated, another is sought, and, after repeated trials, is fitted to the body. Thus new homes are provided as required.

Of course we need not warn any reader not to place these crabs in an aquarium containing other marine creatures; the hermits will kill them all. If, however, a tank can be arranged for hermits only, the peace will probably be kept for some time, they having a wholesome respect for each other's pugnacity, and acting on the international principle, "If you wish peace, be ready for war."

The name "hermit " seems to have been given by those who fancied a resemblance between each crab in its shell and a lonely hermit in his cell. In the West Indies these crustaceans are called "soldiers," their thorax case suggesting the notion of a warrior's breastplate.

The habits of the pea crab (Pinnotheres pisum) are not less remarkable than those of the hermits, and demand a few sen

fended part of its body into the appropriated asylum. If the crab finds the empty shell of a whelk, or any other of a suitable size and shape, the naked part of its body is so firmly fixed in the novel home that it is easily drawn after the animal. If no empty shell can be found, then the fierce crab seizes a whelk, eats the victim, and appropriates its house. When one of these hermits is seen, the fore part of the body is alone visible, the rest being concealed in the cleverly adapted home. To enable the crab thus to crouch into a shell it was necessary to deprive it almost entirely of the two hinder pairs of legs, which are therefore only rudimentary limbs. The observer may wish to have a complete view of so strange a crustacean. Let him be cautious; the hermit is sharp in temper, and a pinch from its mandibles will not be soon forgotten. See how bravely the creature defends its house! Shrinking back as far as possible, it draws in the small claw, bars the entrance with the large one, and holds this in readiness to seize the enemy. Should the hermit at last be gripped without damage to fingers, it is even then 4 question whether its body will not be torn asunder in the endeavour to drag it out. This tenacity of hold arises from a peculiar grasping apparatus on the tail.

tences. These pinnotherians are sometimes not above one-tenth of an inch long, are of a pale-red colour, and inhabit the shells of living mussels. The common edible mussel may often be found with one of these small pea crabs dwelling very com fortably inside the shell, without apparently giving any annoyance to the mussel. The softness of their carapace compels these small crustaceans to find so strange a shelter in the homes of living mollusks. What service the crab renders the mussel is debated, though the old naturalists were very clear upon the matter, holding that the tenant gave warning to its protector of approaching foes, the mussel then closed its shell, and both were safe. "Thus," remarks one writer, "the little crab pays a good rent, by saving the life of his landlady." Sometimes a whole family of pea crabs will be found thus living with their guardian in the utmost harmony, naturalists, however, hint that the mussel would gladly eject the intruders if it were possible. Cockles, oysters, and other mollusks, are also patronised by the pea crabs.

Some

Mussel protectors; so named from the notion that these small crabs guarded the pinna, or mussel, from the cuttle-fish.

The crab's heart is placed just under the carapace, and is simply a strong muscular pouch or ventricle, from which the blood is sent over the body, and also to the gills, resembling in this respect the action of the human heart. The blood is mostly colourless, though sometimes a bluish tint may be noticed.

The mountain crab of Jamaica is declared by epicures to make a most delicious stew when caught at the proper time and seasoned with lime juice.

We must now make a few remarks on the general structure and physiology of these crustacea. Though crabs are classed with decapods, they have, in strictness, but eight feet, the front pair of limbs being mandibles, which serve as hands, and are not intended to aid progression. The well-known sideway motion of crabs is a necessary result of the peculiar manner in which the joints of the legs are hinged one to the other. Lost limbs are usually restored at moulting time, when the crab throws off its old shell. After a claw has been torn away, the blood vessels and nerves shrink at the point of separation, and from the hollow thus formed the new limb afterwards grows. A crab which had lost seven legs in battle, recovered them all about three months after, when the shell was cast. The new limbs were perfect in all respects, but somewhat smaller than the former set.

These repeated castings of so hard a shell, and the extrication of all the complex limbs from their stony covering, are not the least remarkable phenomena in a crab's life. When the animal ceases to increase, these changes doubtless cease; but during growth several such unclothings must occur. Crabs have been taken covered with oysters of seven years' growth, a clear proof that during the whole of that period the shell had not been cast. These crabs had, of course, ceased growing. How a creature of so complex a form withdraws its body from the tightly-fitting shell, leaving the latter, to all appearance, entire, is a puzzling problem. So completely does the rejected covering retain its form that an observer might easily mistake it for another but smaller crab than its late owner. We say smaller, because the animal after moulting is always larger than the coat it has just put off.

The operation is by no means a pleasant one, if we may judge by the symptoms of decided "illness" shown by the crustacean. It ceases to eat, wriggles about, rubs against the rocks, and acts like a creature "out of sorts." A thin skin is prepared under the shell before this is thrown off, and the under coat soon hardens into a new covering. If we take up one of the shells soon after the moult, we may, with close inspection, generally detect a crack where the crust was split when the body was being drawn out.

It has been lately ascertained that the crab undergoes a complete metamorphosis, all the changes having been traced from the egg to the perfect crab. The first form of the young crustacean is utterly unlike the parent, and was formerly a puzzle to zoologists, who, while they named it Zoea, could only guess at its nature. These creatures, after casting their shells, pass into the second state, in which they bear some resemblance to a shrimp. From this condition they at length emerge as perfect crabs. This metamorphosis has now been proved to occur in no less than seventeen genera of short-tailed decapods. The first hint of these transmutations was given by Slabber, a Dutch naturalist, a hundred years ago; and the truth was gradually proved by Mr. Vaughan Thompson, Mr. Couch, and M. Milne-Edwards.

The crab, of course, breathes by gills or branchiæ,+ as they are often called. These occupy two cavities in the chest, the water being admitted to them through a slit in the side of the thorax, and ejected by an opening near the mouth. The animal is able to regulate the outflow of water from the gills by a movable plate which, turning on a pivot, can be opened or shut at pleasure. By raising the carapace a little, the breath†The Greek for gills.

The Greek for land crab.

The nervous system of the crab consists of numerous ganglia (nervous centres) placed in the abdomen and chest, from which the fine nerve-threads radiate through the body. The most important of these nerves are beautifully exhibited in the hermit crabs dissected by Professor Owen, and now to be seen in the museum of the College of Surgeons.

The eyes are compound; each consisting of numerous sixsided tubes, every one of which forms a distinct eye or eyelet. These organs being placed on short tube-like bodies, retractile in some species, all such crustaceans are called "stalk-eyed."

The crab's ears are supposed to be concealed under a plate, on the lower part of the second antenna. If this plate be removed, a fine membrane will be seen, covering a cavity filled with a fluid, in which the nerve of hearing is visible.

The carapace, or shelly covering of the crab, corresponds to the epidermis, or outer skin, in man, but forms, in reality, the skeleton of the crustacea. It generally consists of about twenty-one flat shelly rings, and is formed of carbonate and phosphate of lime. The peculiar colouring matter is produced by the inner skin, or corium, and becomes, under the action of boiling water, of a reddish hue. The lime, phosphorus, carbon, and other elements forming the shell, are secreted by the animals from the sea water.

The crab has found a place in heraldry, several old families having adopted this crustacean among their insignia; and even that warlike and chivalrous king, Francis I. of France, did on one occasion, at least, introduce the animal into his shield. This, however, is said to have been a satirical allusion to the hesitating movements of the English army in France, under the Duke of Suffolk, in 1523.

All crabs discharge a most useful duty, being in fact the scavengers of the sea, consuming the dead animal matter which would otherwise do much to corrupt the waters along the coasts. Thus even the voracity of the crab promotes the well-being of the natural world, and consequently benefits the human race.