Opisthoporus bialatus (von Moellendorff, 1902)
“Durch die Behaarung und die zwei Reihen Borsten, die an Scabrina oder Lagochilus erinnern, sehr ausgezeichnet.” (Möllendorff, 1902)
Möllendorff (1902) original descriptions Cyclotus (Opisthophorus) bialatus – “T. late umbilicata, conoideo-depressa, solidula, subtiliter striatula, costulis membranaceis deciduis obducta, luteo-cornea, strigis castaneis flammulatis latiusculis eleganter picta. Spira breviter conoidea apice submucronato, acutulo, subglabrato. Anfr. 4½ convexi, sutura profunda disjuncti, ultimus supra et infra peripheriam subangulatus, in angulis serie setorum longiusculorum deciduorum indutus, antice longe descendens. Tubulus suturalis brevis, longe ab apertura remotus, retrorsum curvatus. Apertura fere diagonalis, circularis; peristoma duplex, internum breviter expansum, continuum, superne appressum; externum late expansum, superne valde, basi minus dilatatum.”
Kobelt (1912) descriptions on Cyclotus (Opisthophorus) bialatus – “T. parva, late umbilicata, depressa, solidula, subtiliter striatula, epidermide tenui, lutescente, adhaerente induta, strigis fulminulatis supra castaneis, infra peripheriam pallidioribus dein evanescentibus ornata. Spira breviter conica, prominula, summo unicolor castaneo, apice acutissimo, sutura impressa. Anfr. 4½ regulariter accrescentes, inferi ad suturam planati, dein convexi, ultimus circa umbilicum compressus, antice valde descendens, 3 mm pone aperturam tubulo erecto retrorsum spectante insignis. Apertura perobliqua, circularis, plano irregulari; peristoma fusco-albidum, subduplex: internum continuum, haud porrectum, externum tenuissimum, extus late dilatatum et reflexum, supra et ad basin alato-productum, ad columellam subite evanescens. Operculum normale.”
Cyclotus (Opisthophorus) bialatus – “Diam. 10,5, alt. 5,7.” (Möllendorff, 1902); Cyclotus (Opisthophorus) bialatus – “Diam. maj. 10, min. 8, alt 7 mm.” (Kobelt, 1912)
Type locality – “Kelantan? Malacca?” (Möllendorff, 1902)
Other localities – “Sumatra: Silau Dunia Estate, near Tebing Tinggi” (Benthem-Jutting, 1959); “Sumatra: Brastagi, 1750 m alt.” (Benthem-Jutting, 1959); “Sumatra; Hanna Estate, near Kampung Gunting Saga, 10 m alt.” (Benthem-Jutting, 1959); “Sumatra; Ambalutu Estate, near Kisaran, 50 m alt.” (Benthem-Jutting, 1959); “Sumatra; Sungei Kopas Estate, near Kisaran, 100 m alt.” (Benthem-Jutting, 1959)