A girdle tuft with surrounding cuticle bearing black 0.5mm long spicules. Split, Croatia. July 2012. © J. Prkić.
The perinotum (dorsal surface of the girdle) is covered by a tough cuticle bearing abundant 0.5 mm long, erect, translucent colourless and/or black spicules and smaller, denser, usually brownish, spicules, length 0.01- 0.015 mm, that form a felt-like cover.

KEY ID FEATURES : 01 Acanthochitona fascicularis