is commonly considered as an aficidia (see Mytilus, Encycl.) but this is denied by a late author, who seems to have paid great attention to the pearl-fishery at Ceylon. It has never, he says, been ac- curately described. It does not resemble the aficidia of Linnaeus; and as he thinks it may form a new genus, he gives the following account of it:

"The fish is fastened to the upper and lower shells by two white flat pieces of muscular substance, which have been called ears, and extend about two inches from the thick part of the body, growing gradually thinner. The extremity of each ear lies loose, and is surrounded by a double brown fringed line. These lie almost the third part of an inch from the outer part of the shell, and are continually moved by the animal. Next to these, above and below, are situated two other double fringed move- able substances, like the bronchiae of a fish. These ears and fringes are joined to a cylindrical piece of flesh of the size of a man's thumb, which is harder and of a more muscular nature than the rest of the body. It lies about the centre of the shells, and is firmly attach- ed to the middle of each. This, in fact, is that part of the pearl-fish which serves to open and shut the shells. Where this column is fastened, we find on the flesh deep impressions, and on the shell various nodes of round or oblong forms, like imperfect pearls. Between this part and the hinge (cardo) lies the principal body of the animal, separated from the rest, and shaped like a bag. The mouth is near the hinge of the shell, enve- loped in a veil, and has a double flap or lip on each side; from thence we observe the throat (esophagus) defending like a thread to the stomach. Close to the mouth there is a curved brownish tongue, half an inch in length, with an obtuse point; on the concave side of this defends a furrow, which the animal opens and shuts, and probably uses to convey food to its mouth. Near its middle are two bluish spots, which seem to be the eyes. In a pretty deep hole, near the base of the tongue, lies the beard (byssus), fastened by two fleshy roots, and consisting of almost 100 fibres, each an inch long, of a dark-green colour, with a metallic lustre; they are undivided, parallel, and flattened. In general, the byssus is more than three quarters of an inch without the cleft (rim); but if the animal is disturbed, it contracts it considerably. The top of each of these threads ter- minates in a circular gland or head, like the stigma of many plants. With this byssus they fall themselves to rocks, corals, and other solid bodies; by it the young pearl-fish cling to the old ones, and with it the animal provides its food, by extending and contracting it at pleasure. Small shell fish, on which they partly live, are often found clinging to the former. The stomach lies close to the root of the beard, and has, on its lower side, a protruded obtuse point. Above the stomach are two small red bodies, like lungs; and from the stom- ach goes a long channel or gut, which takes a circuit round the muscular column above-mentioned, and ends in the anus, which lies opposite to the mouth, and is covered with a small thin leaf, like a flap. Though the natives pretend to distinguish the sexes by the ap- pearance of the shell, calling the flat ones males, and those which are thick, concave, and vaulted, females, our author, on a close inspection, could not perceive any visible sexual difference."

The pearls are only in the softer part of the animal, and never in the firm muscular column above-mention- ed. They are found, in general, near the earth, and on both sides of the mouth. From the appearance of the shell a judgment may be formed, with greater or less probability, whether it contains pearls or not. Those which have a thick calcareous crust upon them, to which ferula (sea tubes) Tabuli marini irregulariter in- serti, Crista-galli Chamaer lophuris, Lepas tintinabulum, Madrepores, Millipores, Cellipores, Gorgones, Sponges, and other Zoophytes, are fastened, have arrived at their full growth, and commonly contain the best pearls; but those that appear smooth, contain either none, or small ones only.

In the article (Encycl.) intitled, Manner of Fishing for Pearls in the East Indies, we have most unaccount- ably said, that "the best divers will keep under water near half an hour, and the rest not less than a quarter." This is a very great mistake; for Mr. Le Beck assures us, that the time during which a diver is able to re- main under water seldom exceeds two minutes; and that, even after that short period, he discharges, on emerging from the sea, a quantity of water, and some- times a little blood, from his mouth and nose. We have mentioned the danger which the divers run of becoming a prey to monstrous fishes. These fishes are sharks; of which such a dread is justly entertained, that the most expert divers will not, on any account, descend, till the conjurer has performed his ceremonies of enchantment. These consist in a number of prayers, learned by heart, that nobody, probably not even the conjurer himself, understands, which he, standing on the shore, continues muttering and grumbling from sun-rise until the boats return. During this period, he is obliged to abstain from food and sleep, otherwise his prayers would have no avail: he is, however, allowed to drink; which privi- lege he indulges in a high degree, and is frequently so giddy, as to be rendered very unfit for devotion. Some of the conjurers accompany the divers in their boats; which pleases them very much, as they have their protectors near at hand.