1: large inhalent siphon, a rolled extension of mantle, whitish as juvenile, ventral slit visible where rolled sides meet.

2: eye peduncle.

3: head open-wide along ventral mid-line; part of proboscis pouch visible.

4: foot anterior bilaminate, spread into axe-head shape.

5: median groove in foot containing posterior pedal gland.

6: mantle on interior of shell.

7: broad mantle cavity enables passage of large egg capsules; cavity contains ctenidium and osphradium.

8: sole coloured as dorsum of foot, but without opaque lines.

9: foot tapers slightly to rounded posterior

10: mantle on exterior of shell.

Shell length 9.3 mm. Anglesey, Wales, September 2015. Leg. J. Light.