and strong nippers before, one of which is of the thickness of a man's thumb, and is capable of inflicting a severe wound. The tail is furnished with a hook, by which it secures itself in its lodging. They inhabit the empty cavities of turbinated shells, changing their habitation, according to their increase of growth, from the small nerite to the large whelk. Nature denies them the strong covering behind, which it has given to others of this class, and therefore directs them to take refuge in the deserted cases of other animals. They crawl very fast with the shell on their back; and, at the approach of danger, draw themselves within the shell, and, thrusting out the larger claw, will pinch very hard whatever molests them. It is very diverting to observe these animals when they have occasion to change their shell. The little soldier is seen busily parading the shore along that line of pebbles and shells which is formed by the extremest wave, still however dragging its old incommodious habitation at its tail, unwilling to part with one shell, even though a troublesome appendage, till it can find another more convenient. It is seen stopping at one shell, turning it, and passing it by; going on to another, contemplating that for awhile, and then slipping its tail from its old habitation to try on the new; this also is found to be inconvenient, and it quickly returns to its old shell again. In this manner it frequently changes, till at last it finds one light, roomy, and commodious; to this it adheres, though the shell be sometimes so large as to hide the body of the animal, claws and all. It not unfrequently happens that severe contests arise between two of these crabs for some favourite shell. When this animal is taken, it sends forth a feeble cry, endeavouring to seize the enemy with its nippers; which, if it fastens upon, it will sooner die than quit the grasp.

THE common or black-clawed Crab has three notches on the front; five serrated teeth on each side; the claws elevated; the next joint toothed; the hind feet subulated: the colour a dirty green, but red when boiled. It inhabits all our shores, and lurks and burrows under the sand.

It changes its shell once a year, generally between Christmas and Easter, and while it is performing this operation it retires among the cavities of rocks, and under large stones. The Crab is an exceedingly quarrelsome animal, and when it has seized on its antagonist it is not easily compelled to forego its hold. In this situation, the captive has no resource but to relinquish the limb, and nature has provided it with the power of accomplishing this in a very curious manner. It stretches the claw out steady, the claw suddenly gives a gentle crack, and the wounded limb drops off, not, as we might be led to infer from reasoning, at the joint, but in the smoothest part.

SHRIMPS possess long slender feelers, and between them two thin projecting lamina; the claws have a single hooked moveable fang; they have three pair of legs; seven joints in the tail; the middle caudal fin subulated, the four others round and fringed; a spine on the exterior side of each of the outmost. These animals, which are of a delicate flavour, inhabit the shores of Britain in vast quantities, ascend the rivers, and even find their way into the ditches and ponds of salt marshes. Those caught in the sea are, however, much better than those of the rivers.

The Prawn is not unlike the Shrimp, but exceeds it in size, being at least three times as big; and is more pleasing in colour, it having, when boiled, the most beautiful pink tint all over its body. The flesh is better tasted than that of the Shrimp. It has a long horn in front of its head, compressed vertically, which bends somewhat upward, and is serrated both above and below. Sea weeds, and the vicinity of rocks near the shore, are the haunts of the Prawn, which, unlike the Shrimp, seldom enters the mouths of rivers. It usually swims on its back, but when in danger it throws itself on one side, and springs backward to a considerable distance.

THE OYSTER.

THIS genus comprehends the two extensive families of Pectens or Scallops, and Oysters; and there are no less than a hundred and thirty-six species in the whole. In both divisions, the animal is well known as a nutritive and valuable food. Both Scallops and Oysters are found plentifully in the Indian seas, the Mediterranean, the American ocean, and in the European seas, where they constitute a considerable article of commerce. The Scallops produce a sort of coarse byssus: and have the agility of leaping full half a yard out of the sea, at which time they open their shells, and spout out the stale water within them; after which they rapidly sink, taking in fresh water, and closing their shells with a loud snap, which betrays their beds to the watchful fisherman.

Though, by an artificial classification, they are both included in one genus, Nature has impressed a very obvious difference in the external appearance of the Oyster and the Scallop. In their locomotive faculties there is a still stronger distinction. When the tide leaves it dry, the Scallop, by a sudden closing of its valves, assisted by the foot, has the power of springing four or five inches at a jerk, repeating this motion in order to regain its element. In the water, it is able to raise and sustain itself near the surface, turning about in various directions, and on any alarm can suddenly close the valves and sink to the bottom. -The Oyster, on the contrary, is unfurnished either with a foot or with byssus; and its powers of motion consist only in turning either the flat or convex side upwards or downwards; and even to effect this, the animal is said to take advantage of the force of the ebbing or flowing of the water to assist it.

The Oyster excludes its young completely formed; and by the help of a magnifier, the joinings of the little infant shells can be distinctly seen, with all their parts, as perfect as the parent animal, though appearing to the naked eye only as a minute point.

The Oyster respires by means of gills. The water is drawn in at the mouth, which is a small opening in the upper part of the body, and proceeds thence down a long canal, constituting the base of the gills, and so out again, the animal retaining such a portion of air as is necessary for the functions of the body.

THE COCKLE.

Of the Cardium, or Cockle tribe, there are more than fifty species; some or other of which are to be procured on the sandy shores of all the known seas. They are mostly found immersed a few inches deep in the sand. In size the different species vary considerably, some being five or six inches in diameter, and others not more than half an inch. The Cockle has a tolerable degree of locomotive power, in consequence of its triangular yellow foot, which is conspicuous on the shell being opened. With this foot it can also draw into threads its glutinous matter, and thus in a manner anchor itself on the spot that it has chosen for its residence. The opening of the shell is protected by a soft membrane, which wholly closes up the front, except in two places, at each of which there is a small, yellow, fringed tube. Through these tubes the animal receives and ejects the water which conveys nutriment to its body.

The Cardium edule, or Common Cockle, which is the species most common in this country, has a grayish shell, somewhat heart-shaped, with about twentyeight flattish ribs, transversely striated with recurved