Limacinidae: Limacina trochiformis (d’Orbigny, 1834) (‘top-shaped sea-butterfly’)

Synonym(s): trochiformis d’Orbigny, 1836 contorta Sykes, 1905.
Typical shell-length 1.8 mm. Lives in offshore waters in midwater. Native. Occurs all around Australia (QLD, NSW, TAS, VIC, SA, WA and NT); also widespread in warmer oceanic waters worldwide.