A CARTILAGINOUS FISH, which in its general appearance bears a near resemblance to the Lamprey. Its colour is dusky bluish above, and reddish towards the head and tail; its length from four to six inches. The Hag-fish is remarkable for its total want of eyes; its mouth is of an oblong form, with two beards or cirri on each side, and on the upper part four. On the top of the head is a small spout-hole, furnished with a valve, by which it can be closed at pleasure. A double row of pores extends beneath the body, from one extremity to the other, which on pressure exude a quantity of viscid fluid, which, when attacked by large fish, the Hag throws out, so as to cloud the surrounding element in such a manner as to render itself invisible to its assailants. “The habits of this fish are highly singular: it will enter the bodies of such fishes as it happens to find on the fishermen’s hooks, and which consequently have lost the power of escaping its attack; and gnawing its way through the skin, will devour all the internal parts, leaving only the bones and the skin. If put into a large vessel of sea-water, it is said in a very short space to render the whole water so glutinous that it may easily be drawn out in the form of threads.” § III. _Bony Fishes._ [Illustration: THE PILOT-FISH. (_Naucrates ductor._)] THE body of this fish is long, the head compressed, rounding off in front, without scales as far as the operculum. The mouth is small, the jaws of equal length, and furnished with small teeth; the palate has a curved row of similar teeth in front, and the tongue has teeth all along. The colour varies in several species. The Pilot-fish will frequently attend a ship during its course at sea for weeks, or even months together; and there are many curious stories told respecting its habits, in occasionally directing a shark where to find a good meal, and also in warning him how to avoid a dangerous bait. Whether this be true or not will be difficult to determine; but it is certain that this little fish is generally found in company with the shark, and picks up the smaller pieces of food which his predatory master drops, either by accident or design. [Illustration: THE REMORA, OR SUCKING-FISH, (_Echeneis Remora_,)]