Phylum: Charophyta   Family: Desmidiaceae

Staurastrum anatinum var. longibrachiatum W. West & G.S. West 1905

First described and illustrated by West & West (1905: 504, pl. 7: 8-9). It differs little from the nominate variety except in having longer processes, tipped with three large spines.
Cell dimensions: L: 62-111 µm; B: 99-131 µm; Is: 11-12.5 µm.
Found in the plankton of the larger lochs where it is not uncommon.

References: 
Coesel, P.F.M. & Meesters, K.J. (2013) European Flora of the Desmid Genera Staurastrum and Staurodesmus.
West, W. & West, G.S. (1905) Further contribution to freshwater plankton of the Scottish lochs.
West, W., West, G.S. & Carter, N. (1923) A Monograph of the British Desmidiaceae, Volume 5.