Notosinister iwaotakii Kosuge, 1963

Albano, Paolo G., Bakker, Piet A. J. & Sabelli, Bruno, 2019, Annotated catalogue of the types of Triphoridae (Mollusca, Gastropoda) in the Natural History Museum of the United Kingdom, London, Zoosystematics and Evolution 95 (1), pp. 161-308 : 161

Notosinister iwaotakii Kosuge, 1963

Figure 55

Notosinister iwaotakii Kosuge 1963a: 246-247, pl. 16, fig. 27, text figs 3, 10.

Type locality.

Ankyaba, Setouchi-machi, Amami Islands.

Type material.

Holotype: TZM Mo. 13067 (fide Kosuge 1963a; not seen). Paratype: NHMUK 1966149: 1 specimen, Amami Islands, Japan .

Original description.

Shell rather small, extremely inflated spindle-form, acuminated at the summit and narrowed at the body whorl. Protoconch of 4 whorls, tapering to the summit, bearing 2 spiral keels with crossed fine axial threads. Mature whorls 7, suture narrowly grooved and encircled by a fine supra-sutural thread. Sculpture of 3 rows of granules, each row almost equal-sized even in the early whorls, but median one slightly smaller than the other two; granules large, round, connected by broad axial columns and spiral costae which are finely latticed, forming fine square hollows, apart from each other by about half of its diameter and 18 to a whorl. Body whorl has 2 more rows of granules, viz. fourth row encircles the periphery and smaller than upper 3 rows, filth slender row on the base. Anterior canal somewhat elongated and recurved backward, posterior canal forming a deep sinus, shell aperture somewhat extended forward. Colouration slate purple, antepenultimate whorl pale or whitish, anterior canal orange yellow.

Shell length: 4.8 mm.

Remarks: This species is distinguished by its inflated spindle-form, sculpture and colouration, and closely related to N. lucidulus (Hervier), though differs in its shell shape and protoconch which is marked by double spiral keels in contrast to a single keel of the latter species, and also differs from N. amoena (Hervier) in its coloration and shell size. This species is dedicated to Prof. Iwao Taki of the Hiroshima University, who is kind enough to read my manuscript with valuable advices.

Figures

Figure 55. Notosinister iwaotakii Kosuge, 1963, Amami Islands, Japan. A Original figure. B-F, H Paratype, NHMUK 1966149: front (B, C), back (D), side (E, F), microsculpture (H). G NHMUK label. Scale bars: B-F: 1 mm; H: 0.3 mm.