Oval aperture rounded at both ends, often narrower at anterior. Shells 1 to 4 have a silver grey vertex patch (6) within the central amphora area (7). External pale ribs and dark radiating lines or bands visible on interior through the transparent, iridescent shell layer beyond the amphora (8). Shell 5 has probably ceased growth and has covered interior details with an opaque white layer. Translucent concolorous ‘myostracum’(9) left by the pedal retractor muscle. Anterior mantle-attachment scar (10).

Lengths 18, 25, 27, 30 and 46 mm. Great Orme, Wales, July 2011.