Phylum: Charophyta   Family: Zygenemataceae

Mougeotia viridis (F.T. Kützing) V.B. Wittrock 1872

First described by Kützing as Staurospermum viride but that genus does not appear to have been designated. It was moved to Mougeotia by Wittrock (1872: 39). John et al. (2011: 586) record it as cosmopolitan and one of the most abundant Mougeotia species in the British Isles. The zygospore is quadrate with concave sides.
Cell dimensions: L: 40-160 µm, B: 6-9 µm.
Zygospore: 20-32 x 20-32 µm.
Common in the Outer Hebrides. Found in moorland bogs and pools with variable acidity.

References: 
John, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition) The Freshwater Algal Flora of the British Isles.
Wittrock, V.B. (1872) Om Gotlands och Ölands sötvattens-alger.