Length of animal 14.5 mm. North Yorkshire. September 2014. (leg. Paula Lightfoot).
Lower image: live specimen. Ends of valves deeply embedded in girdle (extended and reflected mantle flesh). Dorsal surface of girdle (perinotum) has densely-packed, elongate (50 – 60μm), club-shaped granules with the packed heads giving a mealy appearance. Coloured similarily to valves, with variably-distinct paler bands roughly in line with shell sutures. Edge of girdle fringed by straight, abruptly pointed, longitudinally finely striate spicules (124 X 22μm), often tinted as girdle.
Upper image: portion of girdle from same specimen after immersion in sodium hydroxide solution to reveal more clearly the mealy appearance of packed granules.

KEY ID FEATURES and similar species at: 01 Boreochiton ruber. Length 12mm. North Yorkshire. September 2014. (leg. Paula Lightfoot).