Ditropopsis cincta Vermeulen, Liew & Schilthuizen

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 : 16-17

Taxon classification Animalia Architaenioglossa Cyclophoridae

Ditropopsis cincta Vermeulen, Liew & Schilthuizen sp. n. Figure 14

Holotype. Indonesia, Kalimantan Timur, Sangkulirang Peninsula , Liang Belana near Merabu ( RMNH.5003921 ).

Examined material from Sabah.

Sandakan Province. Meliau Range: Southern slope of Gunung Meliau (leg. M. Schilthuizen, T.S. Liew & A. van Til, V 14344).

Description.

Shell very small, rather thick, somewhat translucent, corneous to brown. Surface shiny or glossy. Spire low-conical with convex sides, apex protruding, slightly oblique. Sculpture. Radial sculpture: fine growth lines, locally grading into fine, densely placed riblets. Spiral sculpture on the last whorl: 2 very distinct cords: 1 peripheral, widest and widely projecting, 1 basal; next to these a fine and inconspicuous spiral striation, particularly below the suture and around the basal cord. Sculpture continuing up to the peristome, but close to the peristome somewhat distorted because crossed by a few slightly more distinct growth lines. Aperture. Peristome simple, not expanded, parietal side attached to the penultimate whorl, basal side moderately angular and somewhat drawn out. Dimensions. Height 1.9-2.0 mm; width 2.5-2.7 mm; h/w 0.70-0.76; umbilicus measured over the basal spiral cord 40-48 % of the shell width; number of whorls 4-4 1/2; height aperture 0.8-0.9 mm; width aperture c. 1.0 mm.

Habitat in Sabah and distribution.

Found in forest on ultrabasic bedrock. Elsewhere also on limestone bedrock, 400-500 m alt. Sabah: Meliau Range. Also in Kalimantan, East part. Endemic to Borneo.

Cross diagnosis.

The spire height of Ditropopsis cincta is intermediate between Ditropopsis imadatei and specimens of Ditropopsis tyloacron without a supraperipheral cord. Next to this, it differs from Ditropopsis imadatei by lacking the flaring outer peristome, and from Ditropopsis tyloacron by its narrower umbilicus.

Etymology.

The name refers to the peripheral keel [cinctus (L.) = girded].