The Collaborative International Dictionary
Turritella \Tur`ri*tel"la\, n. [NL., dim fr. L. turris tower.] (Zo["o]l.) Any spiral marine gastropod belonging to Turritella and allied genera. These mollusks have an elongated, turreted shell, composed of many whorls. They have a rounded aperture, and a horny multispiral operculum.
Wiktionary
n. (context zoology English) Any of the genus (taxlink Turritella genus) (or allied genera) of spiral marine gastropods with an elongated, turreted shell.
Wikipedia
Turritella is a genus of medium-sized sea snails with an operculum, marine gastropod mollusks in the family Turritellidae.
They have tightly coiled shells, whose overall shape is basically that of an elongated cone.
The name Turritella comes from the Latin word turritus meaning "turreted" or "towered" and the diminutive suffix -ella.
Usage examples of "turritella".
Turritellae, Spindle-shells, Cerithia, as well as in the shells with flattened cones, Trochidae, Turbines.