Length 4.1 mm. The expanded foot is an elongate ellipse, broader at the front than at the posterior.
The head (on right of image) consists of a mouth surrounded by a large pinkish-white hood with a red-pink longitudinal band at each side; it has no eyes or sensory tentacles. Instead, there are sensory organs in the microscopic aesthete canals that open on the dorsal surface of the shell.
When live and in good condition, the sole is a striking carmine red, as in this image, but it is less intensely so when fully expanded or in poor condition.
Dorset, England. February 2018. Leg. S. Trewhella.