Notosinister atratus Kosuge, 1962

Figure 51

Notosinister atratus Kosuge 1962a: 83, pl. 9, fig. 5, text figs 9, 13.

Type locality.

Ankyaba, Setouchi-machi, Amami Islands.

Type material.

Holotype: TZM Mo. 13039 (fide Kosuge 1962a, not seen; illustrated in Higo et al. 2001: 51, G1705). Paratype: NHMUK 1966142: 1 specimen, Amami Islands, Japan .

Original description.

Shell small, rather fusiform, inflated, rapidly attenuated to the early whorls, slightly narrowed at the base. Protoconch reddish brown, 2 spiral keels overridden by axial threads. Mature whorls 9 to 10 in number, suture well defined as a shallow groove. Sculpture 3 spiral costae, widely apart from each other and decussated with irregular axial grooves, divided into 26 ill-defined granules, upper row largest, median one faint, and turns to a thread at the antepenultimate whorl and diminished at the earlier whorls. Body whorl has 2 slightly granulated extra-costae, anterior canal slightly recurved, aperture subquadrate. White in colour at the earlier 3 whorls and remainder blackish reddish brown.

Shell length: 5.5 mm.

Remarks: This species is easily distinguished by its peculiar sculpture and colour patterns from the allied form.