Intermediate valves on 37 mm long specimen. Split, Croatia. July 2012. © J. Prkić.
The visible intermediate valves occupy only 30 to 40% of the chiton’s width; width of valve (3 to 3) about same as girdle to one side of it (4).
A broad girdle extension from each side passes between the valves (1).
When the animal is adhering to the substrate, the girdle extensions meet or are only separated by the narrow jugal area measuring about 5% of the animal’s width (2).

KEY ID FEATURES : 01 Acanthochitona fascicularis