Mastonia squalida 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

Mastonia squalida Kosuge, 1962

Figure 62

Mastonia squalida Kosuge 1962b: 126-127, pl. 8, fig. 19, text figs 12, 13.

Type locality.

Ankyaba, Setouchi-machi, Amami Islands.

Type material.

Holotype: TZM Mo. 12253 (fide Kosuge 1962b; not seen, illustrated in Higo et al. 2001: 51, G1695). Paratype: NHMUK 1966145: 1 specimen, Amami Islands, Japan .

Original description.

Shell of medium size, conical, tapering to the summit and narrowed at the base. Protoconch with 2 spiral keels crossed with many axial threads. Mature whorls 12, suture not clear. 2 rows of granules beset in the upper and lower parts of each whorl, a fine spiral thread encircles upper part of its interstices and shell covered with many fine scale-like sculpture. Granules large and equal-sized, 16 to a whorl. Protoconch brown, early 4-5 whorls white, remainder dull reddish violet.

Shell length: 6.5 mm.

Remarks: This species is allied to M. squamosa in shell feature and sculpture, though differs from it in colour pattern and also from T. albogranosa in shell feature, details of sculpture and colour pattern.

Figures

Figure 62. Mastonia squalida Kosuge, 1962, Amami Islands, Japan. A Original figure. B-H Paratype, NHMUK 1966145: front (B, C), side (D, E), back (F), aperture (G), microsculpture (H). I NHMUK label. Scale bars: B-F: 1 mm; G: 0.5 mm; H: 0.2 mm.