F. testa subulata, longitudinal iter plicata, transverse striata: anfractibus septem, convexis: sutura valde impressa; spira acuminata; apice acuta: apertura subovata; labro crenato.
Shell rather slender, turreted, with about twenty longitudinal ribs, running a little obliquely to the left, crossed by numerous transverse, revolving, raised lines, giving the shell a cancellated appearance; whorls seven, convex; suture well impressed; spire gracefully tapering; apex acute; columella slightly arched at the upper part; aperture rather narrow, subovate; canal short, straight, rather wider at the base; labrum thin, delicately crenated by the transverse striae. [53] Length 13/20 inch; breadth 1/4 inch; divergence 22°. Habitat. Casco Bay; taken from the stomachs of haddock in the summer of 1840. It must be regarded as very rare.