The length of the shell attains 60 mm, The oblong, conical shell is rather thin. It is of a reddish-brown color, covered transversely with striae and ridges, with some slightly apparent longitudinal striae. The transverse ridges are raised and very prominent. The
spire is elongated and contains seven whorls. These are convex and depressed at their upper part. The
body whorl is longer than all the others together. The
aperture is elongated, ovate, of a reddish yellow, and slightly emarginated at its base. The outer
lip is thin, forming at its upper and internal part a sort of small canal at its union with the left lip. The
columella is almost straight, subverrucose, and of a reddish yellow. The shell is dull brown with fine ridges along the spirals and a papery outer layer that peels off when dead, but in life is usually encrusted by the commensal bryozoan
Alcyonidium nodosum which gives a slightly nodular velvety appearance in purplish to orangy browns Easily confused in the field with
B. pubescens, which does not reach the same maximum size. ==Distribution==