Taxon classification Animalia Mesogastropoda Diplommatinidae

Palaina tuberosissima sp. n. Figs 118-120

Type material.

Holotype MNHN IM-2000-27467, paratypes MNHN/183 IM-2000-27468, NMBE 516867/20. - Viti Levu, limestone outcrop SE of Nambukulevu, 230 m, rainforest, -18.1366 177.8149, leg. Bouchet, Warén & Dayrat, 20.02.1999.

Material.

Viti Levu, Saweni karst, 50-60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998, MNHN/1; Viti Levu, Tuvu karst, 50 m, dry forest, -17.9332 177.7067, leg. Bouchet, 23.08.1998, MNHN/2.

Etymology.

Adjective, derived from Latin tuber = swelling, and suffix -issimus, -a, -um = very.

Diagnosis.

Shell sinistral, small, faint yellowish, bulb well developed, whorls with widely spaced ribs, peristome with labial callus, columella obliquely twisted with a second columellaris beyond the bulb, a very long spatulate parietalis and a strong palatalis inside the bulb.

Description.

Shell sinistral, small, broadly oval, faint yellowish; protoconch acute, granulated; last whorl not constricted, slightly ascending; bulb well developed; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs, area above the aperture almost smooth; aperture circular, simple, adhered to the last whorl; peristome reinforced by a strong labial callus, and two ear-like processes on the upper edges of the peristome; by oblique view into the aperture columellaris visible; internally, columella obliquely twisted and reinforced, truncate in the lower half forming a basal knob-like tooth, and a second columellaris beyond the bulb; parietum with a very long spatulate parietalis in front of the bulb; a strong palatalis inside the bulb present.

Operculum corneous, outer surface with several concentric lamellae and a single, short raised lamella; internal surface concave, smooth, OD = 0.67.

Measurements.

Holotype (Fig. 118): H = 2.97; D = 1.61; PH = 1.12; PD = 1.21; W = 6.

Distribution

(Fig. 170). Central Viti Levu.

Remarks.

Palaina tuberosissima sp. n. is close to Palaina tuberosa, which differs by having a dense ribbing pattern on the area above the aperture. Possession of a second columellaris makes this species unique, as there is no other diplommatinid species on Fiji with this character.