Phylum: Charophyta   Family: Desmidiaceae

Cosmarium kossinskajae (Willi Krieger & J.H. Gerloff) F.A.C. Kouwets 2025

A reclassification of Kosinskaya’s original form. Apparently only known from the New Siberian Islands and Spitzbergen (see Kouwets 2025: 299).
Single cell dimensions: L: 20.7 µm, B: 19.1 µm, Is: 7.2 µm; Th: 10.7 µm; L/B: 1.09.
The Outer Hebridean cell was found in a shallow, mesotrophic loch with aquatics. Clearly an Arctic-subarctic species.

References: 
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium. Part 1: Text. Part 2: Plates.