(Say, 1822)
Description (shell):
Shell a tall, sharply pointed cone of seven or eight tumid whorls. Sutures are deep and sinuous. Sculpture of prominent broad costae (10-12 per whorl), fine growth lines and numerous low, narrow and cord-like spiral striae; costae do not reach base of body whorl; spiral striae do not form prominent keel over siphonal canal. Aperture is oval, slightly pointed adapically, extended basally into a short siphonal canal. Outer lip is thin (thickened internally in mature shells), with sharp inflection at base of siphonal canal. Inner lip forming broad glaze over columella and body whorl.
Size:
Up to 40 x 20 mm commonly half of this.
Colour:
Yellowish, off-white, or buff, with darker throat.
Animal:
Cephalic tentacles flattened, distal quarter slender, with eyes at junction with broader basal portion. Foot like that of Nucella lapillus . Operculum with lateral nucleus.
Habitat:
On oysters, from lower intertidal to 12 m, hibernating in mud at 7°C or less.
Distribution:
An accidental introduction from the eastern USA, presently confined to the Essex and Kent coasts (Distr. U. cinerea).