Kaliella humilis (Tillier & Bouchet, 1988)

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 : 66

Taxon classification Animalia Stylommatophora Euconulidae

Kaliella humilis (Tillier & Bouchet, 1988) Figure 55

Kionghutania humilis Tillier & Bouchet, 1988: 275. Kaliella humilis (Tillier & Bouchet) Liew et al., 2010: Appendix S1 in online Supporting Information. Type from Malaysia, Sabah, Kinabalu N.P.

Examined material from Sabah.

Interior Province. Crocker Range N.P., West of the km 10 marker on the road Tambunan-Ranau, Mahua Waterfall (leg. M. Schilthuizen, BOR/MOL 2882). West Coast Province. Kinabalu N.P., Summit trail between 3080 and 3330 m (leg. T. Narainan, V 13489, V 13480, BOR/MOL 2675, BOR/MOL 2678, BOR/MOL 2683; leg. T.S. Liew, V 14330, BOR/MOL 6037).

Description.

Shell very small, thin, about opaque, greenish brown, (low) conical with flat or slightly convex sides; apex rounded. Surface shiny. Top whorls moderately convex, outer whorls moderately convex and somewhat shouldered, last whorl angular at the periphery, slightly convex below the periphery. Protoconch whorls convex, with predominant, very fine, well-spaced, thin spiral threads, radial sculpture inconspicuous. Teleoconch: Spiral sculpture predominant, above the periphery with fine, very densely placed, somewhat irregularly spaced, thin spiral threads (30 or more on the fifth whorl); below the periphery with very fine, widely spaced threads, with or without numerous still finer, densely placed grooves in between. Radial sculpture teleoconch: above the periphery with raised growth lines at irregular intervals, most distinctly so just below the periphery; below the periphery the growth lines are less distinct. Umbilicus open, narrow. Dimensions: Height up to 3.3 mm; width up to 4.1 mm; diameters of the first four whorls 0.6-0.7 mm, 1.05-1.15 mm, 1.6-1.7 mm, 2.35-2.50 mm respectively; number of whorls up to 5 7/8; height aperture up to 1.4 mm; width aperture up to 2 mm. Radula: central 3-cuspid; laterals 3-cuspid; marginals serrate with 2 large cones at the tip.

Habitat in Sabah and distribution.

Submontane to subalpine forest on granodiorite and sandstone soil. Alt. 1200-3300 m. Sabah: Mount Kinabalu; Crocker Range. Endemic to Sabah.

Cross diagnosis: Shares the distinct sculpture of spiral threads above and below the periphery with Kaliella microconus , but differs by the wider shell with more convex, slightly shouldered whorls, and the much more numerous and more densely placed spiral threads. The sympatric Kaliella kinabaluensis and Kaliella nephelophila differ unequivocally by the slightly more concave outline of the spire, whorls without a shoulder, and by the absence of spiral threads on the lower surface (a fine sculpture of spiral grooves may be present).