Diancta distorta, 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 : 17

Taxon classification Animalia Mesogastropoda Diplommatinidae

Diancta distorta sp. n. Figs 32-34

Type material.

Holotype MNHN IM-2000-27425, paratypes MNHN/112 IM-2000-27426, NMBE 516872/15. Type locality: Viti Levu, surroundings of Qauia village, secondary wet forest, 20-50 m, -18.0999 178.3999, leg. Bouchet & Warén, 15.03.1999.

Material.

Viti Levu, Wailotua karst, 50-80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25-27.08.1998, MNHN/49, NMBE 516884/5; Viti Levu, surroundings of Laselevu village, 80 m, rainforest, -17.7532 178.1416, leg. Bouchet, Warén & Dayrat, 14.02.1999, MNHN/57, NMBE 516885/5; Viti Levu, Waivisa karst, 50-80 m, rainforest, -17.6879 178.4033, leg. P. Bouchet, 27.08.1998, MNHN/33, NMBE 516886/5.

Etymology.

Latin adjective distortus, -a, -um = distorted.

Diagnosis.

Shell sinistral, very small, teleoconch sculpture of regular fine ribs, last whorl only slightly ascending, aperture circular, detached, internally with strong palatal lamella, columellar plate reduced.

Description.

Shell sinistral, very small, elongate, yellowish; last whorl strongly constricted; protoconch broad, obtuse with a pitted microsculpture; umbilicus closed, concave periomphalum; teleoconch sculpture of regularly spaced fine ribs, with an abrupt change on the last whorl with ribs becoming very coarse and widely spaced; last whorl only slightly ascending; aperture circular, detached from the last whorl; peristome funnel-shaped, doubled; no dentition visible in the aperture by frontal view; internally with strong palatal lamella visible through fresh translucent shells, columellar plate reduced to a knob-like basal denticle.

Operculum corneous, flat, with a relatively long apophysis, OD = 0.35.

Measurements.

Holotype (Fig. 32): H = 2.39; D = 1.54; PH = 0.89; PD = 0.91; W = 5.5.

Distribution

(Fig. 170). eastern part of Viti Levu.

Remarks.

Diancta distorta sp. n. differs from all the other small Diancta species by its elongate shell and the unique combination of reduced columellar plate and opposing palatal lamella. In its outer shell morphology it resembles Diancta densecostulata , but in the latter the aperture is always attached to the penultimate whorl (and differs completely in its inner lamellae).