Ischnochitonidae – Callistoplacinae: Callistochiton antiquus (Reeve, 1847) (‘ancient chiton’)
Synonym(s): antiquus Reeve, 1847 mayi Ashby, 1919 meridionalis Ashby, 1919.
Typical shell-length 40 mm. Lives subtidally under rocks and stones, primarily in slightly silty areas. Native. Endemic to southeastern and southwestern Australia (QLD, NSW, TAS, VIC, SA and WA).