Similar to N.pullus (Linnaeus) and only slightly smaller in size, but differing in the following features: protoconch of 3-34 glassy-fawn embryonic whorls, last whorl carinate, squatter and broader in shape, axial ribs on body whorl wider apart and interrupted anterior to the sutures by a shallow channel giving rise to small sutural nodules; interspaces smooth, lacking the impressed grooves of N.pullus. Columellar callus more orbicular and not pointed anteriorly and always white in colour; dorsal hump smaller and more knoblike and the dark brown blotch present in pullus is absent. Greenish-grey to bluish-grey in colour, ornamented with a narrow white subsutural band and a darker central band on the body whorl; the back of the outer lip usually with 2 dark brown spots, but some individuals uniformly cream or dark brown in colour. Operculum yellowish-brown, minutely serrate on right margin.
TYPE LOCALITY. Siquijor I, Philippines. DISTRIBUTION. From Sri Lanka to China, N.Australia and the Solomon Is. In sand, in the intertidal zone. Type specimens. Three syntypes of N.bimaculosus (A. Adams) are in the British Museum (N.H.), London, No. 197317, and the 16.3 mm long syntype is here selected as the lectotype.
Material examined. SRI LANKA: (LACM); ANDAMAN IS: (ZSI); NICOBAR IS: Little Nicobar I (ZMC); MALAYSIA: Singapore (LACM); INDONESIA: Bali (AMS); Kupang, W.Timor; between Pulau and Dong- gala, Sulawesi; Sunur Beach, Bali; Nusa Tenggara; Pantai Pura, N.of Kupang, W. Timor; Pantai Kelapa Lima, 5 km N. pf Kupang, W. Timor (all coll. McCausland); PHILIPPINES: Marinduque (AIM); Puerto Galera, Min- danao (ZMC); off Luzon; E.coast of Polillo; Puerto Princessa, Palawan group; Siquijor; Tajabas province, Luzon; Negros; Santa Maria, Mindanao; Manila; Cebu; San Vincente harbour, Luzon (all USNM); Miriveles, Bataan (LACM); Batangas Bay (AMS); Matnog I (SDMNH); CHINA: (BMNH); WEST IRIAN: E. of Paipoeri, Koeroedoi I, Geelvink Bay (AMS); PAPUA NEW GUINEA: Rabarua, E.New Britain; Kimbe (both coll. Parkinson); AUSTRALIA: Thursday I, Torres Str. (ZMC); Goode I near Thursday I, 3m (NSMT); SOLOMON IS: Gihili, Bougainville (AMS). Nassarius (Plicarcularia) eniwetokensis Ladd, 1977 (Fig. 104) 1977.