Diameter 8 mm. Adult, no longer with juvenile Maltese cross outline and grey furrows on the wall plates, but four distinct wall plates retained, and a low profile with blackish triangles on the scuta. The terga and tergoscutal flaps are obscured by brown algae. When the rostrum edge is indented (1) the outline of the operculum is a blunt diamond shape.
Non-tidal marine lake, Dee Estuary, Cheshire, England. June 2011.