Trachia serpentinitica Vermeulen, Liew & Schilthuizen

Vermeulen, Jaap J., Liew, Thor-Seng & Schilthuizen, Menno, 2015, Additions to the knowledge of the land snails of Sabah (Malaysia, Borneo), including 48 new species, ZooKeys 531, pp. 1-139 : 48

Taxon classification Animalia Stylommatophora Camaenidae

Trachia serpentinitica Vermeulen, Liew & Schilthuizen sp. n. Figure 41

Holotype.

Malaysia, Sabah, Sandakan Province, Gunung Meliau, South flank (BOR/MOL 3201).

Description.

Shell dextral, medium-sized, thin, opaque, whitish with 3 rather narrow, brown bands: one slightly above the periphery, one below the suture and one basal, peristome white, spire low-conical with slightly convex sides; apex almost flat. Surface dull. Periostracum rather thick, easily peeling off in dead shells, translucent, greenish-corneous, with regularly spread, short hairs. Whorls convex and not shouldered, last whorl rounded at the periphery, convex below the periphery. Protoconch whorls rounded. Teleoconch: growth lines at irregular intervals, locally raised to inconspicuous, rather densely placed, flat riblets. No spiral sculpture. Aperture obliquely rhombiform, distinctly drawn out into a rounded beak on the paratal side, peristome only slightly reflected above the beak, distinctly so below the beak. Umbilicus closed, covered by an extension of the peristome. Dimensions: Height c. 11.5 mm; width c. 18.0 mm; diameters of the first three whorls c. 3.5 mm, c. 7.0 mm, c. 12.0 mm respectively; number of whorls c. 3 7/8; height aperture c. 7.5 mm; width aperture c. 11.5 mm.

Habitat in Sabah and distribution.

Found in primary forest on ultrabasic bedrock. Alt. 600-700 m. Sabah: Gunung Meliau. Endemic to Sabah.

Cross diagnosis.

Uniquely identified among Sabah Camaenidae by its beak-like extension of the palatal side of the aperture. The only Sabah species with a similar beak is the ariophantid Rhinocochlis nasuta (Metcalfe, 1851), which has a flat, sharply keeled, entirely white shell without hairs on the periostracum.

Remarks.

This species may be endemic to the Sabah areas on ultrabasic bedrock.

Etymology.

The name refers that the species is found on serpentinite bedrock.