Exterior sculpture obscured by barnacles (1). Barnacles removed (2). Opaque white interior (3) and apricot sole (4) suggest this might be P. ulyssiponensis, but the high shell, H/L 61% and translucent pallial tentacles devoid of opaque white or orange pigment (5) show it is P. vulgata that has ceased growth and deposited an opaque white layer on the interior. Orange pallial gills (6) around foot, not to be confused with pallial tentacles on the perimeter of the mantle. The sides of the foot (7) are yellowish  on this mature specimen. L. 46 mm. Apex 41 % of  L. from anterior. Great Orme, Wales, July 2011.