Diplommatina maipokhariensis Budha & Naggs sp. nov.

urn:lsid:zoobank.org:act: EF1CC77A-F108-4578-B32E-7EBAF2F9EB22

Figs 4C, 9F

Diagnosis

Measurements (n = 6): SH 2.4–2.5 mm, SW 1.1–1.2 mm, Wh 7.2–7.5; holotype: SH 2.5 mm, SW 1.1 mm, Wh 7.5. Dextral, penultimate and body whorls nearly equal in width. Constriction at the inner edge of the parietal wall of the lip (Fig. 9F). Parietalis long and distinct (Fig. 4C 3). Two vertical palatalis: Vpt1 distinct and strong, running along the constriction; Vpt2 thin, running parallel to Vpt1. Two horizontal palatalis running closely together giving the impression of a single lamella above the columella (Fig. 9F). Columellaris prominent. Columellar tooth distinct. Protoconch smooth, Wh approx. 2.0, with very distinct pits, without radial ribs (Fig. 4C 1). Teleoconch with widely spaced strong radial ribs, evenly distributed on the penultimate and body whorls; about 4–6 ribs/ 0.5 mm (Figs 4C 2, 4C4). Fine spiral striation present. Umbilicus closed. Aperture circular. Peristome with two widely spaced lips; 6–8 ribs between the lips (Fig. 4C4). Both lips slightly reflected.

Etymology

The species name refers to the type locality of Maipokhari, one of the Ramsar sites of Nepal.

Type material

Holotype

NEPAL: Maipokhari, Ilam, 2030 m, Cryptomeria forest, 27.001111 N, 87.92222 E, 25 Dec. 2010, P.B. Budha leg. (CDZMTU034).

Paratypes

NEPAL: 10 shells from the type locality, same data as holotype (CDZMTU 035).

Remarks

The shell of Diplommatina maipokhariensis sp. nov. looks intermediate between the Philippine species D. concolor Quadras & Möllendorff, 1893 (Zilch 1953: p. 28, fig. 156) and the Burmese (= Myanmar) species D. exilis W.T. Blanford, 1863 (Hanley & Theobald 1876: pl. 119, fig. 10). Yet, it differs from both these species by its broader whorls. Diplommatina exilis also differs from D. maipokhariensis sp. nov. in the more slender shell and the absence of spiral striations.

Another slender species is D. exserta Godwin-Austen, 1886 (pl. 49, figs 2, 2a), which is larger and lacks a prominent constriction. The most similar species is D. pullula Benson, 1859 from Darjeeling, but D. maipokhariensis sp. nov. has stronger radial ribs and a smaller shell (SH <2.5 mm) than D. pullula (SH> 3 mm).