Palaina sulcata, 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 : 50-52

Taxon classification Animalia Mesogastropoda Diplommatinidae

Palaina sulcata sp. n. Figs 113-115

Type material.

Holotype MNHN IM-2000-27463, paratypes MNHN/31 IM-2000-27464, NMBE 516866/5. - Viti Levu, Wailotua karst, 50-80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25-27.08.1998.

Material.

Viti Levu, Waivisa karst, 50-80 m, rainforest, -17.6879 178.4033, leg. Bouchet, 27.08.1998, MNHN/21, NMBE 516901/3; Viti Levu, Wailotua karst, near summit Uluitova, 370-390 m, rainforest, -17.7582 178.4166, leg. Bouchet, 28.08.1998, MNHN/1.

Etymology.

Latin adjective sulcatus, -a, -um = with a furrow.

Diagnosis.

Shell sinistral, small broadly oval, yellow to greenish, bulb reduced, aperture with a large horizontal columellaris, a strong palatalis corresponding to a deep furrow on the dorsal side of the last whorl, elongated parietalis present.

Description.

Shell sinistral, small to medium sized, broadly oval, faintly yellow to greenish; protoconch acute, granulated; last whorl not constricted, ascending; bulb reduced; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs, area above the aperture almost smooth; aperture subquadrate, with a double lip, and two ear-like processes on the upper edges of the peristome; adhered to the last whorl; aperture with a large horizontal columellaris in a central position; internally, columellaris forming a large horizontal lamella of approximately one whorl, slightly bent upwards towards its end; opposite a strong palatalis corresponding to a deep furrow on the dorsal side of the last whorl; an elongated parietalis and a faint bulb lamella present.

Operculum corneous, outer surface with indistinct concentric lamellae and a single, short raised lamella; internal surface concave, smooth, OD = 0.66.

Measurements.

Holotype (Fig. 113): H = 3.13; D = 1.92; PH = 1.31; PD = 1.38; W = 5.

Distribution

(Fig. 170). Eastern Viti Levu.

Remarks.

Palaina sulcata sp. n. is unmistakable for its columellaris, which is unique among all Fiji diplommatinids, because it is formed like a classical columellaris, i.e. a horizontal lamella running into the interior of the shell twisting around the columella. The columella itself is not transformed. Another unique feature is the strong palatalis with the corresponding furrow in the last whorl.

Palaina sulcata sp. n. is provisionally placed in Palaina , because there is no bulb formation in Diancta , but a constriction of the last whorl, and the columella is usually transformed to form a columellar plate, not present here in Palaina sulcata .