Diancta subquadrata, Neubert, Eike & Bouchet, Philippe, 2015

Neubert, Eike & Bouchet, Philippe, 2015, The Diplommatinidae of Fiji - a hotspot of Pacific land snail biodiversity (Caenogastropoda, Cyclophoroidea), ZooKeys 487, pp. 1-85 : 20

Taxon classification Animalia Mesogastropoda Diplommatinidae

Diancta subquadrata sp. n. Figs 41-43

Type material.

Holotype MNHN IM-2000-27431, paratypes MNHN/21 IM-2000-27432, NMBE 516877/5. Type locality: Viti Levu, limestone outcrop SE of Nambukulevu, 230 m, rainforest, -18.1366 177.8149, leg. Bouchet, Warén & Dayrat, 20.02.1999.

Etymology.

Latin prefix sub = somewhat, and adjective quadratus, -a, -um = squared; with reference to the shape of the aperture.

Diagnosis.

Shell sinistral, broad, small, brownish, ribbing pattern changing from coarse on the upper whorls to fine on the medium and coarse on the last whorl, aperture circular, columellar plate broad.

Description.

Shell sinistral, broadly oval, small, brownish; last whorl considerably constricted; protoconch large, 1-1.5 whorls, pitted; umbilicus closed, periomphalum narrowly concave; ribbing pattern on teleoconch of coarse and spacious ribs on the upper whorl, fine and dense on the intermediate whorls, and coarse and widely spaced again on the last whorl; last whorl slightly ascending and detaching from the last whorl; aperture circular, peristome funnel-shaped, doubled, peristomial rims connected by a broad parietal shield; no pleats visible in the aperture; columellar plate broad, not subdivided, no inner lamellae present.

Operculum corneous, flat, with a long apophysis, OD = 0.59.

Measurements.

Holotype (Fig. 41): H = 3.29; D = 2.02; PH = 1.35; PD = 1.55; W = 5.

Distribution.

Only known from the type locality.

Remarks.

Diancta subquadrata sp. n. is very similar to Diancta densecostulata , but differs by its broadly expanded peristome, reduced columellar plate, and complete absence of internal lamellae.