Georissa pyrrhoderma Thompson & Dance, 1983
“Most of the shells comprising the type series are weathered and encrusted and few are unblemished. The holotype is a fresh specimen but has a small puncture in the penultimate whorl behind the insertion of the lip. G. pyrrhoderma belongs to a group of Bornean species that also includes G. borneensis Smith. The group consist of species having broadly conical, reddish shells. G. pyrrhoderma is distinguished from G. borneensis by its sculpture of conspicuous spiral threads. Other aspects of the shell cannot be adequately compared because of insufficient material of G. borneensis. The two species are geographically remote from each other on Borneo and on Banggi Island.” (Thompson & Dance, 1983)
Thompson & Dance (1983) original descriptions on Georissa pyrrhoderma – “Shell small, adults about 1.9-2.1 mm long. Orange-red in color; interior hyaline. Broadly conical, about 0.79-0.86 times as high as wide. Spire very slightly convex in outline. Whorls of spire relatively small and with a deeply impressed suture. Whorls 2.8-3.1. Protoconch nearly circular and bulbous. Subsequent whorls strongly inflated and uniformly rounded; sculptured with relatively weak spiral threads and numerous close growth striations; about 18-21 spiral threads on penultimate whorl above insertion of lip; spiral threads usually absent on base if shell. Occasional specimens with a supraperipheral spiral row of small compressed whorl. Umbilical callus slightly concave, very wide compared with other Bornean species; not bounded laterally by a narrow crest. Aperture sub-ovate in shape; relatively large, height about 0.48-0.54 times length of shell. Parietal-columellar margin straight. Axis of aperture at 28-34° to shell axis. Plane of aperture at 26-34° to shell axis. Peristome uniformly thin, straight in lateral profile.”
Georissa pyrrhoderma – “Length of shell, 1.92-2.23 mm; width of shell,. 1.64-1.80 mm; height of aperture, 0.99-1.12 mm.” (Thompson & Dance, 1983)
Type locality – “Borneo, Sarawak, First Division, western side of Gunong Selabor, Semabang entrance to Lobang Batu Cave. Gunong Selabor is an isolated limestone mountain south of Serian, in southwestern Sarawak (00°55’N, 110°25’E)” leg. Wilford/1962 (Thompson & Dance, 1983)