Taxon classification Animalia Stylommatophora Ariophantidae

Microcystina consobrina Van Benthem Jutting, 1959 Figure 28, 32

Microcystina consobrina Van Benthem Jutting, 1959: 145; Liew et al. 2010: Appendix S1 in online Supporting Information. Type from Indonesia, Sumatra, Brastagi.

Examined material from Sabah.

West Coast Province. Kinabalu N.P., Kotal route between 2292 and 3112 m (leg. T.S. Liew, J. Lapidin, Safrie & Jasilin V 14326; V 14325, BOR/MOL 4003).

Description.

Shell very small, thin, translucent, pale yellowish green to yellowish brown, approx. lenticular; spire moderately elevated, conical with a rounded apex. Surface shiny, glossy below. Whorls moderately to distinctly convex. Protoconch without spiral sculpture; with fine, densely placed, low radial riblets towards the teleoconch, but slightly coarser than on the teleoconch. Teleoconch: Spiral sculpture above the periphery absent or inconspicuous, below the periphery with numerous fine, well-spaced, continuous, shallow, rather vaguely outlined grooves. Radial sculpture teleoconch: above the periphery with very fine, very densely and regularly placed, low riblets; below the periphery with some irregularly spaced growth lines only. Umbilicus open, narrow; columellar side of the peristome somewhat thickened but not covering the umbilicus. Dimensions: Height up to 1.4 mm; width up to 2.3 mm; diameters of the first three whorls 0.5-0.6 mm, 0.8-1.0 mm, 1.4-1.6 mm respectively; number of whorls up to 4 1/4; height aperture up to 1 mm; width aperture up to 1.2 mm.

Habitat in Sabah and distribution.

Primary forest on granodiorite soil, 2200-3200 m alt., elsewhere at 0-1700 m alt. Sabah: Mt. Kinabalu. Distribution: Sumatra; Bali.

Cross diagnosis.

Uniquely characterized within Group 2 by the fine and dense radial ribbing above the periphery.

Elsewhere, Lamprocystis exigua Von Moellendorff, 1897, from Java to Flores, (see Van Benthem Jutting 1950: 447), is most similar. It differs by having a larger first whorl (diameter 0.7-0.8 mm).

Remarks.

The description includes extralimital material as well. The Kinabalu material has slightly coarser radial riblets than the type.