Shell up to 30.0 mm in length, elongate-ovate, teleoconch of 4½-5 slightly convex to almost flat- sided whorls, protoconch usually worn, but of 1% smooth embryonic whorls; sculptured with few or more numerous axial ribs which number from 12-18 on the penultimate and from 13-24 on the body whorl, ribs somewhat thickened at sutures and producing obsolete sutural nodules; interspaces narrow or wide, sculptured with close-set, flattish spiral cords which become rugose basally and number from 7-10 on the penultimate and from 16-20 on the body whorl, siphonal fasciole short and broad and with a few oblique cords. Aperture moderately narrow, thickened but not prominently variced, interior with 15-16 lirate denticles, columella narrowly calloused, laminate anteriorly, sometimes with a basal fold and with 2-5 small denticles and a prominent parietal denticle, siphonal notch and anal canal prominent. Uniformly white to creamy-white in colour. TYPE LOCALITY. Wallwich Bay [Walvis Bay], S.W. Africa (plicatella); Batangas Bay, Luzon I, Philippines, 38 m = error! (nivea); Port Alexander, S. Angola, 24 m (angolensis); shore of lagoon, Sth. of Bogenfels, Late Tertiary of S.W. Africa (scopularcus). DISTRIBUTION, From southern Angola, S.W. Africa to Port Alfred, South Africa. From the inter- tidal zone to a depth of 35 m. Type specimens. Two syntypes of N.plicatellus (A.Adams), are in the British Museum (N.H.), Lon- don, No.1973157, and the specimen measuring length 24.4 mm, width 13.7 mm, is here selected as the lectotype (pl.34, fig.8). Three syntypes of Nassa nivea A.Adams, are in the same Institution, No.1973156, and the specimen measuring length 23.3 mm, width 12.9 mm, is here designated as the lectotype (pl.34, fig.9). The types of N.angolensis Odhner, are in the Natural History Museum, Goeteborg, and the worn, juvenile holotype of N.scopularca Barnard, is in the South African Museum, Cape Town, No.A-9230, length 14.4 mm, width 7.7 mm. Material examined. SOUTHWEST AFRICA: Walvis Bay (BMNH; USNM); SOUTH AFRICA: Port Alfred (USNM). Literature records. ANGOLA: Port Alexander, 24 m (Odhner, 1923); Mossamedes Bay, 15-20 m; Mossamedes Beach; Praya-Amelia Bay, 15-35 m (all Dautzenberg 1912); Great Fish Bay (Barnard 1959); SOUTHERN AFRICA: Angra Pequena; Table Bay; Saldanha Bay (all Barnard 1959). Barnard (1969) changed his concept of "N.scopularca Barnard, 1959". He reported the species as still living at Langebaan, Saldanha Bay, and stated that it was questionable whether the Bogenfels clays really were as old as Late Tertiary, and suspected that scopularca may eventually be shown to be a mere variant of N.plicatellus.