Diancta dilatata, 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 : 14-16

Taxon classification Animalia Mesogastropoda Diplommatinidae

Diancta dilatata sp. n. Figs 29-31

Type material.

Holotype MNHN IM-2000-27423 paratypes MNHN/662 IM-2000-27424, NMBE 516878/50. Type locality: Viti Levu, Saweni karst, 50-60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998

Material.

Viti Levu, Tuvu karst, 50 m, dry forest, -17.9332 177.7067, 23.08.1998, leg. Bouchet, MNHN/301, NMBE 516882/20; Viti Levu, Qalimare karst, Toga village, 30-130 m, dry forest, -17.9953 177.5768, 21.08.1998, leg. Bouchet, MNHN/120, NMBE 516883/15; Viti Levu, Qalimare karst, East of Natawatawadi, 40 m, dry forest, -17.9816 177.6266, 21.08.1998, leg. Bouchet, MNHN/1.

Etymology.

Latin adjective dilatatus, -a, -um = broadened.

Diagnosis.

Shell sinistral, large, broad, aperture broad and circular, sculpture of coarse, widely spaced ribs, columellar plate reduced.

Description.

Shell sinistral, large, stout and broad, of a dull brown colour; last whorl considerably constricted; protoconch broad, obtuse with a pitted microsculp ture; umbilicus closed, very narrow periomphalum; teleoconch sculpture of coarse, widely spaced ribs, with a few stronger ribs on the last third of the last whorl; last whorl ascending; aperture broad and circular, disconnected from the last whorl; peristome funnel-shaped, doubled; apertural rims connected; no dentition visible in the aperture by frontal view; columellar plate reduced, with a narrow basal almost denticle-like callus, no other lamellae present.

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

Measurements

(Fig. 29). H = 3.89; D = 2.48; PH = 1.65; PD = 1.83; W = 6.

Distribution

(Fig. 170). Four neighbouring localities in central Viti Levu.

Remarks.

Diancta dilatata sp. n. differs from Diancta subquadrata sp. n. by its larger aperture and the much coarser ribbing pattern. In Diancta martensi , the aperture is subquadrate, and the peristome is connected to the penultimate whorl. Diancta subquadrata sp. n. and Diancta martensi differ from Diancta dilatata sp. n. by their well developed columellar plate.