Phylum: Miozoa   Family: Ceratiaceae

Ceratium hirundinella  (O.F. Müller) Dujardin

Widespread but not particularly common. Fairly adaptable to nutrient levels in deeper water of lochs

References: 
John, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition) The Freshwater Algal Flora of the British Isles