Taxon classification Animalia Stylommatophora Trochomorphidae

Geotrochus whiteheadi (E.A. Smith, 1895) Figure 90

Helix conicoides Metcalfe var. parva E.A. Smith, 1887: 132. Trochonanina whiteheadi E.A. Smith, 1895: 106. Type from Malaysia, Sabah.

Examined material from Sabah.

West Coast Province.Kinabalu N.P., Carson’s Falls (leg. J.J. Vermeulen, V 12710); Serinsim-Numbuyukon trail between 700 and 1680 m (leg. T.S. Liew, BOR/MOL 4024, BOR/MOL 4104); Monggis-Tambuyukon trail at 2080 m (leg. T.S. Liew, BOR/MOL 4110); Mesilau trail at 1948 m (leg. T.S. Liew & J. Lapidin, BOR/MOL 4393); Summit trail between 1700 and 1784 m (leg. T.S. Liew, BOR/MOL 4392; leg. T.S. Liew & Dominik, BOR/MOL 4396).

Description.

Shell rather small, rather thin, about opaque, pale corneous to pale brown, low-conical with approx. flat sides; apex not protruding. Surface with a silky luster above the periphery, shiny below. Whorls: Apical whorls moderately convex, outer slightly convex, slightly shouldered; suture impressed in the inner whorls, hardly so in the outer, coinciding with the periphery; last whorl acutely angular, (slightly) compressed at the periphery, moderately rounded below the periphery. Protoconch 2 1/8-2 1/4 whorls, smooth. Teleoconch. Radial sculpture: above the periphery growth lines, slightly raised locally; below the periphery indistinct growth lines only. Spiral sculpture: last whorl with a sharp, somewhat pinched peripheral keel; start of fifth whorl with c. 15 thin, moderately spaced spiral threads: 1-2 slightly more distinct close to the periphery, as well as 13-14 inconspicuous above these; no spiral sculpture below the periphery. Umbilicus closed. Peristome thickened and reflexed. Dimensions: Height 5.5-6.0 mm; width 12.3-12.5 mm; h/w 0.44-0.48; diameters of the first 4 whorls 1.2-1.4 mm, 2.1-2.4 mm, 3.4-3.8 mm, 5.2-5.8 mm respectively; number of whorls 6 1/4-6 3/8, height aperture 3.3-3.5 mm; width aperture c. 6.5 mm.

Habitat in Sabah and distribution.

Mixed montane forest, 700-2100 m alt. Sabah: Mount Kinabalu only. Endemic to Sabah.