Taxon classification Animalia Stylommatophora Camaenidae

Amphidromus psephos Vermeulen, Liew & Schilthuizen sp. n. Figure 40

Holotype . Malaysia, Sabah, Interior Province, Pun Batu c. 30 km West of Sepulut (RMNH.5003951).

Examined material from Sabah.

Interior Province. Pun Batu c. 30 km West of Sepulut (leg. J.J. Vermeulen, V 1311).

Description.

Shell sinistral, rather large, rather thin but rather solid, opaque, white, top whorls with or without some oblique, pale brownish-purple markings, spire high-conical with convex sides to approx. narrowly ovoid; apex narrowly rounded. Surface shiny. Whorls: top whorls convex, other whorls slightly convex, flat or slightly concave just below the suture; last whorl rounded at the periphery, slightly convex below the periphery. Protoconch whorls rounded, minutely punctate. Teleoconch: few growth lines at irregular intervals, locally slightly raised. Spiral sculpture: a faint, very fine, dense stration locally present. Aperture slightly obliquely elliptic, peristome distinctly reflected on the palatal, basal and columellar side. Umbilicus closed, or rimate, a narrow pore underneath the reflected columellar peristome. Dimensions: Height 24-25 mm; width 11-12 mm; number of whorls 5-5 1/2; height aperture 11.0-11.5 mm; width aperture 6.5-7.5 mm.

Habitat in Sabah and distribution.

Found in shrubby forest on limestone bedrock. Alt. c. 500 m. Sabah: Interor, Pun Batu only. Endemic to Sabah.

Cross diagnosis.

The small size, combined with the narrow spire uniquely identifies this species within in the genus Amphidromus .

Etymology.

The name refers to the size of the shell [psephos (Gr.) = pebble].