Rare abnormal variant of L. cinerea with only six valves. Examination of such a variant of Callochiton septemvalvis may explain the misleading specific epithet (= seven valves) given to it by Montagu (1803) as it, like other chitons, usually has eight valves.
Skye, Scotland. March 2022. © N. Roberts

Reference: Montagu, G. 1803. Testacea Britannica or natural history of British shells, marine, land, and fresh-water, including the most minute: Systematically arranged and embellished with figures. London, J. White. [p. 3] www.biodiversitylibrary.org/item/78694#page/53/mode/1up

KEY ID FEATURES and similar species at: 01 Lepidochitona cinerea