Phylum: Charophyta   Family: Desmidiaceae

Xanthidium octocorne C.G. Ehrenberg ex J. Ralfs 1848

First described by Ehrenberg in Ralfs (1848: 116, pl. 20: 2) and illustrated by Jenner.
Cell dimensions: L: 16-24 µm; B: 15-20 µm; Is: 4.5-6 µm; Sp: 6-12 µm; overall LxB: 29-45 x 25-40.
Zygospore: minus projections: 17-19 µm; overall: 28-32 µm.
Widespread and common in acidic moorland pools and lochs, especially with plankton.

References: 
Coesel, P.F.M. & Meesters, K.J. (2023 second edition). Desmids of the Lowlands.
John, D.M. & Williamson, D.B. (2009). A Practical Guide to the Desmids of the West of Ireland.
Ralfs, J. (1848). The British Desmidieae.
Van Westen, M. (2024). Sieralgen in Drenthe.