Length 42mm. Dorset, England. April 2017.
A & B: Head to the right. Girdle covered by epibiota and detritus caught on its coat of spicules.
C: As B, but with some detritus and spicules brushed off.
This old specimen has had its coloured tegmentum eroded to expose the white inner layers of the valves. Parts of the valves and the girdle between them are stained with rust coloured, probably ferrous, deposits. The large spicules that can form a fringe around the rim of girdle have been eroded and coated in detritus.
This specimen is 42mm long; another at the same intertidal site was over 50mm long. Maximum for the species is 60mm; Britain’s largest chiton.