Trochomorpha rhysa 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: 97-98

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Trochomorpha rhysa Tillier & Bouchet, 1988


Taxon classification Animalia Stylommatophora Trochomorphidae

Trochomorpha rhysa Tillier & Bouchet, 1988  Figure 79

Trochomorpha rhysa  Tillier & Bouchet, 1988: 257. Type from Malaysia, Sabah, Mount Kinabalu.

Examined material from Sabah.

West Coast Province. Kinabalu N.P., Summit trail between 2526 and 3200 m (leg. T.S. Liew, BOR/MOL 3979, V 14493; leg. K. Kittel,V 4806); near Laban Rata (leg. M. Schilthuizen & P. Koomen, BOR/MOL 2783); Mesilau trail between 2404 and 2680 m (leg. T.S. Liew, BOR/MOL 3983, BOR/MOL 3977, BOR/MOL 3981, BOR/MOL 3978); Kiau-Spurs trail 2688 and 2944 m (leg. T.S. Liew, J. Lapidin & Safrie, BOR/MOL 4403, BOR/MOL 3980); Kotal’s route at 2992 m (leg. T.S. Liew, J. Lapidin, Safrie & Jasilin, BOR/MOL 3982); Sayap-Nunuhon trail between 2480 and 2640 m (leg. T.S. Liew, Dominik, J. Lapidin & Jasilin, BOR/MOL 3984, BOR/MOL 3986, BOR/MOL 4401).


Shell rather small, rather thin, about opaque, (pale) yellowish brown to pale greenish brown, moderately low-conical with approx. flat sides; apex not protruding. Surface with a silky luster above the periphery, shiny below. Whorls somewhat convex, outer whorls slightly shouldered; suture impressed, coinciding with the periphery; last whorl distinctly angular but not or hardly compressed at the periphery, rounded below the periphery. Protoconch 2 1/8-2 1/4 whorls, with dense radial riblets except at the apex; transition to teleoconch sculpture abrupt. Teleoconch. Radial sculpture: above the periphery rather densely placed, more or less regularly spaced riblets, slightly more irregular on the last whorl and fading towards the aperture; below the periphery growth lines only. Spiral sculpture: last whorl with a peripheral thread; start of fifth whorl with 14-19 fine, rather low and wide spiral threads or more or less equal strength, forming nodes over the radial sculpture (less distinctly so on the earlier teleoconch whorls), threads on the last whorl dissolving in rows of granules; no spiral sculpture below the periphery. Umbilicus closed. Peristome moderately thickened and reflexed, more distinctly so on the columellar side. Dimensions: Height 6.0-6.8 mm; width 10-12 mm, h/w 0.57-0.62; diameters of the first 4 whorls 1.4-1.5 mm, 2.3-2.5 mm, 3.7-4.0 mm, 5.5-6 mm respectively; number of whorls 5 3/4-6, height aperture 3.0-3.8 mm; width aperture 5-6 mm.

Habitat in Sabah and distribution.

Montane and sub-alpine forest on sandstone and granodiorite bedrock, 2400-3300 m alt. Sabah: Mount Kinabalu only. Endemic to Sabah.

Cross diagnosis.

See under Trochomorpha haptoderma  and Trochomorpha thelecoryphe  .