Phylum: Charophyta   Family: Desmidiaceae

Cosmarium moniliforme var. limneticum West & G.S. West

This is the larger of the varieties, especially the isthmus. Found in circumneutral waters but status unknown

References: 
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands
West, W. & West, G.S. (1908) A Monograph of the British Desmidiaceae, Volume 3