Calliostomatidae – Calliostomatinae: Calliostoma (Sinutor) incertum (Reeve, 1863) (‘sinistral top-shell’)
Synonym(s): incertum Reeve, 1863.
Typical shell-length 15 mm. Lives subtidally and offshore on sponges. Native. Endemic to southeastern and southwestern Australia (NSW, TAS, VIC, SA and WA).