Wentletrap

wentletrap, also called staircase shell, or ladder shell, any marine snail of the family Epitoniidae (subclass Prosobranchia of the class Gastropoda), in which the turreted shell—consisting of whorls that form a high, conical spiral—has deeply ribbed sculpturing. Most species are white, less than 5 cm (2 inches) long, and exude a pink or purplish dye. Wentletraps occur in all seas, usually near sea anemones, from which they suck nourishment. The common wentletrap (Epitonium clathrus) occurs in European waters; the money wentletrap (E. indianorum) is common from Alaska to Mexico.