Ditropopsis imadatei (Habe, 1965)

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 : 17-18

Taxon classification Animalia Architaenioglossa Cyclophoridae

Ditropopsis imadatei (Habe, 1965) Figure 15

Ditropis imadatei Habe, 1965: 117. Type from Brunei, Bandar Seri Begawan.

Ditropopsis sp. “nov.”, Schilthuizen 2004: 94.

Examined material from Sabah.

Interior Province. Crocker Range N.P., Ulu Kimanis, trail 5 of Crocker Range Scientific Expedition (leg. UMS Students, V 12747).

Description.

Shell very small, rather thick, somewhat translucent, white to pale greenish. Surface shiny or glossy. Spire conical with convex sides, apex somewhat protruding, hardly oblique. Sculpture. Radial sculpture: fine growth lines, locally grading into fine, densely placed riblets. Spiral sculpture on the last whorl: 5 cords: 1 peripheral, 1 basal, very distinct, and 2 much thinner and more inconspicuous umbilical cords; next to these a fine spiral striation locally present. Sculpture continuing up to the peristome. Aperture. Peristome double, the outer thickened and distinctly expanded, parietal side attached to the penultimate whorl in fully adult shells, basal side angular, distinctly drawn out; the inner peristome slightly protruding from the outer, slightly expanded, basal side only slightly angular and slightly drawn out. Dimensions. Height c. 2 mm; width 2.0-2.2 mm; h/w c. 0.9; umbilicus measured over the basal spiral cord 25-31% of the shell width; number of whorls c. 4 1/8; height aperture c. 1 mm; width aperture 1.0-1.2 mm.

Habitat in Sabah and distribution.

Primary forest on sandstone and limestone soil, 200-800 m alt. Sabah: Crocker Range. Also in Sarawak; Brunei; Kalimantan, East part. Endemic to Borneo.

Cross diagnosis.

Uniquely identified among the Sabah species by the double peristome.

Elsewhere, Ditropopsis moellendorfi Boettger, 1891 (Maluku) has a double peristome, but a much flatter shell with more numerous spiral cords.