It is not to be disputed that the discoveries which have taken place among the vermes of those testaceous bodies since the time of Linnæus, have introduced us to a far more extensive acquaintance with the beings of this nature than Linnæus could have possessed. The term Limax, which Linnæus applied not only to the animal inhabitants of the Voluta family, but also to the Buccinum, the Strombus, the Murex, the Trochus, the Turbo, in short to almost every genus of the Univalves, and some even of the Bivalves could not fail to excite remark. It could scarcely be conceived that in the very ample range of the creation which those genera embraced, such uniformity could prevail, and the subsequent observations of various Naturalists have tended fully to assure us that the Linnæan character of the animal inhabitants of the testaceous tribes was much too vague and comprehensive. There are indeed, it must be confessed, a considerable number of those testaceous bodies, the animals of which are still unknown, and may possibly so remain, but forming our conclusions, from the great multitude that has been recently discovered, and the number of those which have been examined with anatomical attention, we may presume, with safety, that the Linnæan Limaces ought properly to be divided into several distinct genera. How far a methodical distribution of the shells themselves, founded upon the zoological distinctions of the animal inhabitants, may be admissible in our cabinets appears less certain. The greater number of those shells, of which the animals are totally unknown, present insuperable objections; and the attention of collectors in the formation of the Conchological Cabinet, so rarely extend beyond the more obvious characters which the structure of the shells present, that we can scarcely deem it practicable. The animal of the shell before us, Voluta pyrum, has been ascertained and well described by Lamarck, De Montfort, and other writers; it has the head armed with two obtuse feelers of a club-like form; the eyes advanced and placed at the base, at the outerside of those feelers; the mantle or fleshy covering terminating in an elongation folded into a kind of tube above the head; the foot, or disk, strong and muscular, and armed with a small round horny operculum.