The final costa is rarely sufficiently thickened to form a slight labial varix (6). The exterior rim of the aperture (7) is usually thin, smooth and white without periostracum on live and dead shells.
Heights, 1: W. Anglesey, March 2014, 22.4 mm, 2: Scourie, Scotland, September 1975, 30.8 mm, 3: Blackwater, Essex, September 2019, 27.2 mm Leg. S.Taylor, 4: Weymouth, Dorset, April 2012, 27.6 mm, 5: Tarragona, Spain © J. Prkić.

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