The shell is an elongate cone of up to nine tumid whorls. Sutures are deep, sinuous, without subsutural band. Profile is slightly cyrtoconoid, turreted. Sculpture of strong, flexuous, buttress-like costae, dipping sharply to sutures, overlain by numerous thin, sharp spiral ridges separated by deep, narrow grooves. There is no conspicuous interaction between spirals and growth lines. Protoconch of three whorls; smooth, followed by interacting spiral ridges and crescentic costae. Aperture is narrow, elongate, almost parallel-sided; outer lip is thin, in older shells serrated, with varix; anal sinus is semicircular, with everted rim.
Up to 15 x 5 mm, more common half of this size.
Cream or light horn coloured with brown spiral band at sutures and variable number of brown spirals on last whorl; costae are pale.
Sublittoral, on soft substrata at 20-50 m.
Not common. From the Mediterranean to the western coasts of the British Isles (Distr. M. smithi).