Length 26 mm. Dorset, England. April 2017.
The only part of the valves visible on the live animal is the coloured tegmentum. Both absolutely, and relatively to the tegmentum, the girdle on A. fascicularis is the largest of all British chitons . The visible intermediate valves occupy only 30 to 40% of the chiton’s width.

KEY ID FEATURES : 01 Acanthochitona fascicularis