Phylum: Charophyta Family: Desmidiaceae
Cosmarium rectangulare Grunow 1868
Relatively common in moorland pools and loch-margins. Tolerant of acidic to mildly alkaline waters
References:
West, W. & West, G.S. (1908) A Monograph of the British Desmidiaceae, Volume 3
John, D.M. & Williamson, D.B. (2009) A Practical Guide to the Desmids of the West of Ireland
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands