| Closing mechanism: primary system present Closing mechanism: secondary system absent Colour: shell transparent Colour: shell aperture dark-brown Distribution: Pacific Ocean Distribution: Indian Ocean Distribution: -30¡N-0¡N Distribution: Indo-Malayan waters Distribution: 0¡S-30¡S Distribution: depth epipelagic Embryonic shell: droplet shaped Lock angle: 64¡ Lock angle: 61¡ Operculum: absent Radula: with formula 1-1-1 Radula: with 09 rows Shell: straight seemingly two valves Shell: calcareous Shell: straight Shell: greatest width below middle Shell: bend caudally Shell anteriorly: caudal septum closing shell Shell anteriorly: protoc. I usually lost Shell aperture: slit-like Shell aperture: without thickened borders Shell character: anteriorly curved dorsally Shell character: globular Shell dorsal side: ribs present Shell dorsal side: 5 longitudinal ribs Shell dorsal side: vaulted strongly Shell lateral side: aperture occupies a large part Shell length (height): 05.6 mm Shell length (height): 06.0 mm Shell length (height): 05.8 mm Shell sculpture: transverse clearly striated Shell top angle: 140¡ Shell top angle: 150¡ Shell ventral side: ribs absent Shell ventral side: vaulted strongly Shell width (diameter): 04.5 mm Side angle: >100¡ Spines of shell: caudal spine bent dorsally Spines of shell: caudal spine short Spines of shell: length laterals=length caudal Spines of shell: 4 callus lines present Spines of shell: lateral spines small Spines of shell: lateral spines not bent Whorls of shell: absent |