The typical form of this attractive little cap-shaped shell is smooth, and of orange-brown colour, with a few sky-blue longitudinal lines. It lives on Laminaria and Fucus seaweeds, to a depth of about 15 fathoms. The variety laevis is a gerontic form of the species that is thicker, larger, and flattens out towards the margin, where the sculpture is more pronounced. Such shells are always ledged, the early portion being exactly like normal pellucidus. Pilsbry (1891) remarked that the laevis variety is due to station, such individuals being found partly embedded in the stems of Fucus.