Heliacus ponderi (Garrard, 1978)
Common in the Solitary Islands Marine Park. Endemic to Australia, recorded from New South Wales, across the south to southern Western Australia and including Tasmania.
Frequents subtidal areas among zoanthids.
Note helical operculum and newly deposited egg mass on food source zoanthid, Zoanthus robustus. Grows to around 9mm shell width.