Left: live head of 29mm specimen. LWS. Isle of Lewis, Scotland. April 2018. Leg. D.W. McKay & S.Taylor. Right: preserved specimen. Orkney. February 2015. Leg. P. Lightfoot per J. Porter.
Left: head fully extended while attached to glass. The head is anteriorly convex to fit the curve of the shell, and posteriorly concave fitting round the anterior of the foot and extending laterally as mouth lappets.
Right:When preserved, the mouth may gape widely and its fleshy surround may contort to form a hood.

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