Plesiotrochidae: Plesiotrochus monachus (Crosse & Fischer, 1864) (‘common monk-shell’)

Synonym(s): monachus Crosse & Fischer, 1864.

Typical shell-length 25 mm. Lives subtidally amongst seagrass, especially in sheltered environments. Native. Endemic to southeastern and southwestern Australia (NSW, TAS, VIC, SA and WA). In Tasmanian waters, this is a widespread species, though seldom common.