Shell elongate ovate, extremely shining, height 19.3 mm, width 9.8 mm. Planktotrophic protoconch of 3.75 smooth whorls, last 1.5 carinated. Teleoconch of 5.5 whorls, first 3 axially ribbed, other ribs smooth. Suture deeply channeled. First three whorls with a subsutural spiral groove, axial ribs coronated. On next whorls subsutural spiral groove gradually indistinct, suture with undefined crenulations. Base of last whorl with 5 axially striated spiral grooves. Towards edge of outer lip 3-5 low axial ribs, lip not thickened, with 4-5 prominent denticles. Inside lip with 14 strong and deep lirae, siphonal area with 5 prominent, axially striated spiral grooves.
Columella laminate and with an abapical tooth, inside with 15 lirae. Parietal denticle strong, anal canal wide and prominent.
Color bright light brown with darker axial streaks, more prominent at the suture, and with 2 lighter spiral bands on the last whorl. Outer lip and columella white, inside aperture brown.
Intraspecific variation: Dead collected specimens have lost their brilliant shine and are off white. Size varies from about 18.3 mm to 27.5 mm.

Live-taken specimens of N. radians sp. nov. are easy to identify by their brilliant shine, the characteristic color pattern and the last 2 whorls of the shell which are nearly smooth. A species comparable with N. radians sp. nov. is N. thachi Dekker, 2004, which can be distinguished from N. radians sp. nov. by its more elongate shape and its size: up to 36 mm. Moreover, N. thachi has a clear subsutural groove. The recently described Nassarius (Zeuxis) nanhaiensis Zhang, 2013, from the South China Sea, at first sight, looks, very much like N. radians sp. nov. The latter differs however, in the number of protoconch whorls: 3.75 against 2-2.50 in N. nanhaiensis. The protoconch of N. nanhaiensis is described as smooth, whereas N. radians sp. nov. is prominently carinated. Other differences are the number of the axial ribs on the first 2 to 3 teleoconch whorls and the color of the shell. Nassarius radians sp. nov. is extremely glistening.
Another species with similarities with N. radians sp. nov. is Nassarius comptus (A. Adams, 1852). Nassarius radians sp. nov. can be distinguished from N. comptus by the conspicuously different ribs on the three penultimate whorls: N. comptus has thick ribs, whereas the ribs of the new species are less prominent. The protoconch has fewer whorls, the callus is strictly limited to the columella and the shell is less shiny than in N. radians sp. nov.
The redescription of N. comptus by Cernohorsky (1984) is based on a taxonomic concept that includes several nominal species as synonyms, making comparison with N. radians sp. nov. somewhat problematic. The lectotype NHMUK 1969531/1 designated by Cernohorsky (1984: 146), and the syntype NHMUK 1969531/2 of N. comptus, are illustrated here for the first time in color. A comparison of the lectotype of N. comptus with the holotype NHMUK 1973021 of Nassa cinnamomea (A. Adams, 1852) shows that the latter is distinguished from N. comptus by its slenderer shape and the presence of a subsutural groove. They represent two different species in our opinion. The first three teleoconch whorls of the lectotype of N. comptus are far more prominently ribbed than those of the syntype. Also the taller shape, the callus and the bands mismatch. In this respect, the para-lectotype of N. comptus seems to be a specimen of N. haldemani (Dunker, 1847).
The taxonomic status of N. comptus and the great number of taxa considered synonyms by Cernohorsky (1984: 146), correctly or incorrectly, is such a complex problem that it exceeds the objectives of the present paper and deserves a separate study for the future. Kool (2006: 98), supported on the discussion of Kase and Kinjo (1996:199), already noticed the erroneous synonymisation of Nassarius cinnamomea with N. comptus.

Philippines, the Solomon Islands and Vanuatu, alive at depths between 53-180 m. Type locality
Vanuatu, Canal du Segond, 15°31.6'S, 167°12.4'E, 58-59 m