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.