Shell elevated-conical, with convex sides, imperforate, yellowish-white, with black-brown square spots, running from the suture to the keel, and more numerous narrow spots and streaks of the same colour on the base; nucleus wanting; remaining whorls 7,5, slightly convex, separated by a narrow channelled suture. Upper whorls slightly worn, with 3 and 4 spiral lirae, which increase to 5 in number on the last 4 or 5 whorls; they are crossed by slightly undulating ribs, with beads where they cross each other, the lowest of the lirae forming the peripheral keel is the largest, and on this one the beads have a tendency to become squamate, (but not so much as in P squamocarinatum). Last whorl descending in front and here the ribs form irregular lamellae; periphery of last whorl angular. Base convex, with 5 spiral, beaded lirae, the interstices with strong, irregular lamellae. Aperture nearly round, angular at the upper part and very faintly so at the base of the columella. Outer and basal margins thin, thickened interiorly, with 10 conspicuous lirae, that nearest the columella toothlike. Columella cylindrical, with a groove round its upper part, running at its left side towards a square notch, formed by a square, toothlike fold at the basal part and the most proximal of the internal lirae of the base, below the notch are one large and two small denticles; parietal wall callous. Alt. 10,2 MM diam. maj. 6,3 mm; apert. alt. 3,5 mm, lat. 3,25 mm