Euthymella isaotakii Kosuge, 1962

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

Euthymella isaotakii Kosuge, 1962

Figure 54

Euthymella isaotakii Kosuge 1962b: 124, pl. 8, fig. 18, text figs 6, 8.

Type locality.

Ankyaba, Setouchi-machi, Amami Islands.

Type material.

Holotype: TZM Mo. 12094 (fide Kosuge 1962b; not seen, illustrated in Higo et al. 2001: 50, G1685). Paratype: NHMUK 1966143: 1 specimen, Amami Islands, Japan .

Original description.

Shell of medium size, broad conical and narrowed at the base. Colour very distinctive, protoconch light brown, early 3 whorls white and the next one brown, the remainder olive bistre. Protoconch of 4 whorls, conical with a spiral thread overriden by axial threads. Mature whorls 10, suture distinct but not deep, having a fine supra·sutural thread. Sculpture of 3 rows of granules, strongly connected spirally and axially, and latticed. Granules large and equal·sized, spirally elongate and apart from each other by one third of its diameter, 14 to a whorl. 2 extra rows of granules on the body whorl. Anterior canal tubular.

Length: 6.8 mm.

Remarks: This species is easily distinguished by its colour dattern, sculpture and shell feature. It is closely related to E. regalis Jousseaume and E. pannata Laseron, though differing in number of rows of granules, shell feature and colour pattern.

This species is named in memory of the late Dr. Isao Taki, who was kind enough to guide me in malacology.

Figures

Figure 54. Euthymella isaotakii Kosuge, 1962, Amami Islands, Japan. A Original figure. B-H Paratype, NHMUK 1966143: front (B, C), side (D, E), back (F), peristome (G), aperture (H). I NHMUK label. Scale bars: B-F: 1 mm; G, H: 0.5 mm.