Diplommatina miriensis Godwin-Austen, 1917

Figs 5A, 9G

Diplommatina miriensis Godwin-Austen, 1917: 577, fig. 4D.

Diplommatina (Metadiancta) miriensis – Gude 1921, 342. — Ramakrishna et al. 2010: 95 — Budha et al. 2015: 7.

Diagnosis

Measurements (n = 5): SH 1.5–1.6 mm, SW 0.8–1.0 mm, Wh 5.5. Dextral, whorls regularly increasing, penultimate and body whorl nearly equal in width. Constriction at the middle of the parietal wall (Fig. 9G). Parietalis very weak, nearly invisible (Fig. 5A 3). One vertical palatalis along the constriction and one very strong horizontal palatalis just above the columella (Fig. 9G). Columellaris thin and weak. Columellar tooth very weak to nearly absent. Protoconch smooth, Wh approx. 1.5, with very distinct small pits evenly distributed all over, no radial ribs (Fig. 5A 1). Teleoconch with dense radial ribs; about 10–13 ribs/ 0.5 mm on the penultimate whorl; 8–9 ribs/ 0.5 mm on the body whorl towards the aperture (Figs 5A 2, 5A 4). Very fine spiral striation present. Umbilicus closed. Aperture circular. Peristome with two lips; under high magnification 6–10 ribs visible between the lips (Fig. 5A 4). Parietal wall with thin callus. Angular edge of the peristome curved (Fig. 5A 3, A 4); basal edge of peristome rounded; outer lip thin, inner lip thick. Parietal wall of the aperture hardly reaching half of the body whorl.

Material examined

NEPAL: 1 shell, Deurali, Syabru, Langtang National Park, 2412 m, 27.805037 N, 85.387862 E, 25 Apr. 2008, P.B. Budha leg. (CDZMTU 036); 3 shells, Okhareni, Shivapuri-Nagarjun National Park, 2326 m, 27.813051 N, 85.4217 E, 22 Jun. 2007, R. Devkota and N. Kohar leg. (CDZMTU 037); 1 shell, Baghdwar, Shivapuri-Nagarjun National Park, 2500 m, 27.8133 N, 85.3877 E, 25 Apr. 2008, P.B. Budha leg. (CDZMTU 037b); 4 shells, Cholangpati, Langtang National Park, 3443 m, 28.110154 N, 85.334238 E, 19 May 2008, P.B. Budha leg. (CDZMTU 038); 7 shells, Raniban, Balaju, Kathmandu, 1840–1902 m, 27.745997 N, 85.287240 E, 12 Mar. 2009, S. Khanal leg. (CDZMTU 058).

Remarks

D. miriensis is the smallest species reported in the present study. Similar sized species are D. godwini Möllendorff, 1898 from Naga Hill, NE India, and the south Indian D. minima Beddome, 1875. Diplommatina godwini has more whorls (>7) than D. miriensis, while the peristome of D. minim a has no curved angular edge.