TURBINATED. (_Turbo_, a top,) Top-shaped. The term is applied generally to those shells which are large at one extremity, and narrow to a point at the other. _Ex._ Trochus, fig. 358; Turbinellus, fig. 382. TURBINELLUS. Auct. (_A little top._) _Fam._ Canalifera, Lam. Siphonostomata, Bl.--_Descr._ Turbinated, thick, wide near the apex, generally tuberculated; spire short, depressed, mammillated; aperture rather narrow, terminating anteriorly in an open canal; outer lip thickened within; columella having from three to five prominent, compressed, transverse folds. The species of this genus are mostly tropical.--_Obs._ The Turbinelli are a well marked genus of marine shells, the species of which are numerous. No fossil species are known. The genus Cancellaria makes the nearest approach to Turbinellus in some characters, but may be distinguished by the roundness of its form, the raised lines inside the outer lip, and the obliquity of the folds on the columella. Fig. 382 to 384. TURBO. Auct. (_A top._) _Fam._ Cricostomata, Bl. Turbinacea, Lam.--_Descr._ Turbinated, solid, ventricose, generally grooved or tuberculated; spire short, pointed; aperture generally rounded, sub-effuse anteriorly, entire; operculum shelly, solid, incrassated on the outer side, horny and sub-spiral on the inner side. The Turbines are mostly tropical.--_Obs._ The only certain means of distinguishing this extensive genus of marine shells from Trochus, is the operculum, which in the latter genus is horny, spiral, and composed of a great number of whorls. The Trochi, however, are in general more conical, and flatter at the under side of the whorls, and this constitutes Lamarck's distinction between the genera. T. setosus, fig. 368. TURGID. (_Turgidus._) Puffed up, swollen, inflated. This term is applied synonymously with Ventricose. TURRICULA. Humph. MELANIA, Auct. TURRICULACEA. Bl. The seventh family of the Order Polythalamacea, Bl. containing the genus Turrilites, fig. 483. TURRILITES. Lam. (_Turris_, a tower; [Greek: lithos], a stone.) _Fam._ Turriculacea, Lam. Ammonacea, Bl.--_Descr._ Chambered, turrited, spiral; septa sinuous and lobate, perforated by a siphon; aperture rounded, with the outer lip expanded. This genus, which is distinguished from the other Ammonacea by having the spire produced, _i. e._ not being convolute, consists of several species, occurring only in chalk-marl. Fig. 483. TURRIS. Montf. A genus composed of those species of MITRA, Auct. which have the whorls angulated, with the aperture lengthened and undulated. TURRITED. The spire of an univalve shell is said to be _turrited_ when the whorls of which it is composed are regulated so as to have the appearance of little turrets rising above each other, as in Mitra, fig. 431.