Phylum: Charophyta Family: Desmidiaceae
Cosmarium subprotumidum Nordstedt 1876
A north-western distribution in Britain but not common. Found in vegetated margins of lochs and pools tolerating circumneutral waters
References:
West, W. & West, G.S. (1908) A Monograph of the British Desmidiaceae, Volume 3
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands