Shell of medium size, conical, elongate, solid, white. Protoconch of 3 short, smooth, glassy whorls, continuing the line of the spire. Mature whorls 6, sides nearly
flat, deeply channelled at the sutures, body whorl with only a slight curve to the base. Sculpture rugosely clathrate, the axials, 18 on the body whorl, stronger than the spirals, which number 5 on the body whorl and 3 on the earlier whorls. The axials are broad, and rise at the intersections into prominent, rounded gemmules, the interstices forming small, deep pits. Basal fold strong, indented by the axial ribs, which are continuous across the intervening deep channel. Aperture ovate, slightly oblique, outer margin thickened internally, and with a very broad external varix which is crossed by a continuation of the spiral ribs, columella sinus deep. Length 4,6 mm.
Locality.—Cape Sidmouth, holotype and 1 paratype selected from a series in the Australian Museum (C2662) collected by A. R. Henn.
Remarks.—This species has a similar protoconch to and the same number of axials and spirals as P. ultima, but is smaller, has a whorl less, is narrower, and the sculpture is much more rugose, the large gemmules at the intersections and the small, deep intervening pits giving it a very different facies.