Phylum: Charophyta   Family: Desmidiaceae

Staurastrum manfeldtii G.B. Delponte 1878

First described and illustrated by Delponte (1878: 64, pl. 13: 6, 7, 9-19). A variable species, which has spawned numerous infraspecific taxon over time. Coesel & Meesters (2013: 116) have made strides to sort the taxonomy but it is probably still ongoing.
Overall cell dimensions: L: 35-65 µm; B: 45-100 µm; Is: 8-13 µm.
Widespread in circumneutral to slightly acidic waters, such as in the plankton of lochs and marginal vegetation of moorland pools.

References: 
Coesel, P.F.M. & Meesters, K.J. (2013). European Flora of the Desmid Genera Staurastrum and Staurodesmus.
Delponte, G.B.(1878). Specimen Desmidiacearum subalpinarum.
West, W., West, G.S. & Carter, N. (1923). A Monograph of the British Desmidiaceae, Volume 5.