Phylum: Charophyta   Family: Desmidiaceae

Cosmarium cantalense F.A.C. Kouwets 2025

Named after the Cantal department of the Pyrenees, it was found in the tychoplankton of several oligo-mesotrophic pools and lakes. These small smooth-walled cells are confusing and need to be compared with the similar, but doubtful,C. bioculatum and equally doubtful C. tenue. With the work accomplished by Kouwets (2025) a clearer picture should now arise.
Cell dimensions: L: 13.7-16 µm, B: 13.2-14.8 µm, Is: 5-6.1 µm; Th: 8-9 µm, L/B: 1.04-1.09.
Found in slightly acidic, mesotrophic habitats. Because of the uncertainty over identification its status in the Outer Hebrides is unknown.

References: 
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium.