26 Margarites helicinus album. COMPARISON image of Margarites groenlandicus. Orkney, Scotland. © A. Skene.

26 Margarites helicinus album. COMPARISON image of Margarites groenlandicus. Orkney, Scotland. © A. Skene.

Spirally ribbed, depressed, globose shell. Distinct umbilicus, no longitudinal slit or ‘chink’. Shell cream, orange or pink with no iridescence externally, but with blue-green refraction within aperture. Rare in Britain, only north coast Scotland, Orkney and Shetland.

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