HELIX, the Snail, in zoology, a genus belonging to the order of vermes teſtacea. The ſhell conſiſts of one ſpiral, brittle, and almoſt diaphanous valve; and the aperture is narrow. There are 60 ſpecies, principally diſtinguiſhed by the figure of their ſhells. They are of various ſizes, from that of a ſmall apple to leſs than half a pea. Some of them live on land, frequenting woods and gardens, or inhabiting clefts of rocks and dry ſand-banks. Others of them are aquatic, inhabiting ponds, deep rivers, and the ocean. The principal ſpecies are,
1. The Janthina, with a violet-coloured ſhell, is remarkable for the extreme thinneſs of its texture, which breaks with leaſt preſſure, and ſeems therefore entirely calculated to keep the open ſea, or at leaſt to ſhun rocky ſhores. It inhabits the ſeas of Europe, eſpecially the Mediterranean; thoſe of Aſia and Africa; and
and also the ocean. The living animal, when touched, exudes a juice, which stains the hands of a violet colour. Dr. Hawkesworth, in his account of Cooke's voyage, mistakes this shell for that which yielded the purpura of the ancients. But whoever looks into Pliny, can never have the least idea that the thin shell aforementioned could be the same with it. They had several shells which yielded the purple dye: but these were all rock-shells*, and very different, both in figure and hardness, from the little helix jacintha; which is not calculated for the neighbourhood of rocks, as already mentioned. Vid. Plin. lib. v. cap. 1. and lib. ix. cap. 60, 61. See also Don Ant. Ulloa's voyage to South America, book iv. ch. 8.
2. The pomatia, or exotic snail, with five spires, most remarkably ventricose, and fasciated with a lighter and a deeper brown, is a native of France, where it inhabits the woods; but has been naturalized in England, where it inhabits the woods of the southern counties. It was introduced, as it is said, by Sir Kenelm Digby; whether for medical purposes, or as food, is uncertain: tradition says, that to cure his beloved wife of a decay was the object.—They are quite confined to our southern counties. An attempt was made to bring them into Northamptonshire, but they would not live there.—These are used as a food in several parts of Europe during lent; and are preserved in an escargatoire, or a large place boarded in, with a floor covered half a foot deep with herbs, in which the snails nestle and fatten*.—They were also a favourite dish with the Romans, who had their cochlearia, a nursery similar to the above. Fulvius Hirpinus† was the first inventor of this luxury, a little before the civil wars between Cæsar and Pompey. The snails were fed with bran and sodden wine. If we could credit Varro‡, they grew so large, that the shells of some would hold ten quarts! People need not admire the temperance of the supper of the younger Pliny§, which consisted of only a lettuce a-piece, three snails, two eggs, a barley-cake, sweet wine and snow,—in case his snails bore any proportion in size to those of Hirpinus.—Its name is derived not from any thing relating to an orchard, but from operculum, it having a very strong one. This seems to be the species described by Pliny, lib. viii. c. 39. which he says was scarce; that it covered itself with the opercule, and lodged under ground; and that they were at first found only about the maritime Alps, and more lately near Velitæ. [See Plate CLVIII. the figure half the natural size.]
3. The hortensis, or garden-snail, is in form like the last, but lesser, and not umbilicated and clouded, or mottled with browns.—These are often used with succesi in consumptive cases.