Thracia villosiusucla is a rather flat sub-rectangular bivalve. It can be up to 3 cm long and shell white in colour and quite brittle. The surface of the shell has fine granulation and this can be seen with a X10 hand lens.

Marine Bivalve Shells of the British Isles Thracia villosiuscula (Macgillivray, 1827) To size: To 30mm. Shell Structure: Brittle. Equivalve: Inequivalve, RV more convex than LV. Equilateral: Inequilateral, beaks behind midline. Outline: Oval; anterior margin broadly rounded, posterior dorsal margin straight, becoming truncated.