Buccinum. An oblong or oval shell, the opening of which is terminated at the base by an oblique groove, without any sensible canal, or external border. Bru guIere has divided the Bliccina of Lin. nzus into the genera Buccinum, Terebra, Cassidza, and Purplira. Under the genus Buccintim are therefore here comprised tumid shells, with from three to ten spiral turns ; a summit generally flattish ; a sur face rarely even ; the predominating co lours dull ; the lip extended more or less in a bow, and rarely jagged.
Cassidza. A tumid shell, the opening longer than wide, terminated at its base by a short canal, recurved towards the back of the shell; the columella plaited in the lower part. This genus of Bru gulere is intended to comprise the helmets (casques) of Gualteri. Klein, and others.
Terebra. A turriculated univalve; the opening grooved in the lower part : the base of the columella twisted or oblique.
Purpura An oval shell, generally yid& spines, or tuberculated ; the openingter minating in a very short canal, the extre mity of the canal grooved out, the base of the columella finishing in a point. The shells included in this genus by Brugulere are not those species which have been hitherto considered as Purpurz, by Dar genville and others, and which belong to the genus Murex ; but those species which appear to connect the genus Buc cinum and Murex. The opening of these shells is rather large, oval, round, up wards, and more contracted in the inferior part : the right lip bas but little thick ness, and is grooved or notched ; the left expands with a wrinkled ridge, %I/Wok terminates in the groove.
Volute. A cylindrical, or oval, uni valve shell, grooved out at the base, but without a glitter ; the opening longer than wide ; and the columella plaited. The division of this genus by Linnzus is very clear and useful; but Lamarck pro. poses a still nicer distinction ofthe shells of this genus, by dividing them into e.ght genera. 1. Voluta, an oval shell, more or less bellied, summit obtuse or mammil lated ; the base grooved, but without a gutter; the columella with several plaits, of which -the lowest are largest and longest ; as in vnluta musics 2. Oliva, sub cylindrical, grooved at the base ; the turns of the spire separated by a channel; the columella striated obliquely, as in Voluta olive. 3. Ancilla, oblong, a short mke, base of the opening hardly groov ed: a swelling, or oblique roll, at the base of the columella. 4. Mitra, fusiform
or turriculated, spire pointed at the sum. mit, the base grooved out, without a gut ter; the columella with plaits, the lowest being the least, as in Voluta episcopalis. 5. Columbella, marked by a swelling on the internal face of the right edge, as in Voluta mercatoria. 6. Marginella, the right edge emarginated, as in Voluta yes pertilio. 7. Cancellaria, the right edge grooved internally ; and the base of the opening almost entire, as in Voluta reti culata. 8. Turbinella, sub.turbinated, canaliculated at its base, with transverse plaits on the columella Ovula. A tumid shell, more orless elon gated at the extremities ; the edges roll. ed inwards; the opening longitudinal, not dentated on the left side. This genus is formed by Lamarck from shells, which had been comprised by Linnaus in his genus Bulls. The shells of the genus Ovula differ from those of Cyprza, chiefly by the absence of teeth from the left side. Bulls volva, ovum, spelta, verrucosa, and gibbosa, of Linnaus, are placed under this genus.
Terebellum, a shell nearly cylindrical, pointed at the summit ; the opening lon gitudinal, narrow upwards, and hollowed out at its base ; the columella truncated. This genus is formed, by Lamarck, of the Bulla terebellum of Linnaus, which he has removed from the genus Bulls, and has placed in this genus, as in termediate between the Ovula and the Olives.
Cypnea. A convex, univalve shell, the edges turned inwards : the opening long and narrow, and toothed on each side. The shells of this genus are so distinctly characterized, as to have escaped that confusion which has taken place in many other genera.
Conus. A conical, convoluted univalve ; the opening of the length of the shell ; linear, without teeth, and hollowed out at the top ; the columella smooth. The ge neric characters are here an determinate, as not to have left any opportunity for changing the acceptation of this genus, as established by Linnaeus.
Vermicularia. A tubular shell, twisted in an irregular spiral, in general adhering to some body, and furnished with an operculated opening. The shells with which Lamarck has formed this genus were blepded by Linnaeus with the Ser pula ; but the animals which inhabit these shells are very different from the 'Fere brella, which are the only inhabitants of the true Serpi'la.