Phylum: Ochrophyta Family: Ophiocytiaceae
Ophiocytium cochleare (Eichwald) A.Braun
Probably common in the plankton of pools and lochs, especially on moorland
References:
John, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition) The Freshwater Algal Flora of the British Isles