Shell up to 16.0 mm in length but frequently smaller, ovate, light in weight, teleoconch of 3½-5 convex and slightly inflated whorls, protoconch of 3-3½ glassy, carinate embryonic whorls; sculptured with usually numerous, slightly irregular, thin axial ribs which are either continuous to the outer lip or become obsolete on body whorl towards the varix, ribs number from 30-53 on the penultimate and from 25-45 on the body whorl, axial ribs frequently weak and irregular on early spire whorls; spiral sculpture consists of fine or prominent spiral striae which number from 9-17 on the penultimate and from 18-38 on the body whorl, basal striae becoming rugose cords, siphonal fasciole with 5-9 oblique cords, sutures with a row of small nodules. Aperture moderate in size, outer lip thickened and broadly variced, interior with 5-16 denticles in mature individuals, columella narrowly calloused and with 2-13 small denticles, siphonal notch weak, anal canal moderately distinct in adult individuals. Uniformly off-white, fawn to straw-yellow in colour, some specimens with 2-3 brownish bands on body whorl and some individuals have the axial ribs stained with brown. Operculum yellowish-brown and simple at margins. TYPE LOCALITY. Molucca Passage, Indonesia, 0°11'S & 127°25'E, 397 m (crebricostatus); Red Sea, 24°48'N & 35°25'E, 535 m (sporadica); Dilemmi, Red Sea (beccarii); Niki Niki, Timor, Plio/Pleistocene of Indonesia (kampeni). DISTRIBUTION. From the Red Sea to Madagascar, the Andaman Is and the Tuamotu Archipelago. In mud, subtidal to a depth of 472 m. Type specimens. Syntypes of N.crebricostatus (Schepman) are in the Zoological Museum, University of Amsterdam, and the mature syntype, length 6.7 mm, width 4.0 mm, is here selected as the lee- totype (pl.33, fig.4). The holotype of N. beccarii Bisacchi, is in the Museo Civico de Storia Natural, Genoa, length 11.0 mm. The type of Nassa sporadica Sturany, could not be located in the Natural History Museum, Vienna (Dr. E.W.Wawra in litt.), and the taxon remains a nomen dubium. The type of N.kampeni Koperberg, is probably in the Geology Department, University of Amsterdam. Material examined. RED SEA: Aden (NMV); MADAGASCAR: off Madagascar, 12°34'S & 48°15'E, 395 m (Natal Mus.); ANDAMAN IS: (ZSI); INDONESIA: Sanana Bay, E. coast of Sulu Besi, 22 m (ZMA); off Pendek I, Buton Str., Celebes, 393 m (USNM); Java, 7°29'S & 114°49'E, c. 240 m (ZMC); PHILIPPINES: Tanon Str., off Refugio I, 472 m at 17°C (USNM); 13°32'N & 121°07'E, 130-137 m (MNHNP); Balayan Bay, Luzon, 392 m (USNM); off Arcua Pt., Luzon, 234 m (coll.Norton); AUSTRALIA: Northern Territory: Arafura Sea, c. 161 km N. of Croker I, 9°30'S & 132°34'E, 124 m; Queensland: Capricorn Channel, 23°08'S & 152°16'E, 155 m; E. of Northwest 1, 23°15'S & 152°24'E, 284 m; 30 km E. of North reef, 23°11'S & 152°14'E, 188 m (all AMS); PAPUA NEW GUINEA: Laing I, Hansa Bay, 65 m (coll. Tursch).