Phylum: Charophyta   Family: Desmidiaceae

Cosmarium anisochondroides  F.A.C. Kouwets 2025

A recently described species similar to C. anisochondrum Nordstedt 1878. The latter species has two distinctive supraisthmial granules, which helps separate them. It possibly enjoys a different ecology, but more finds are needed to establish that.
Cell dimensions: L: 31.4-35.8 µm; B: 29.2-31.8 µm; Is: 10.3-12.2 µm; Th: 17.3-20.6 µm; L/B: 1.03-1.14.
Being recently described, the status is the Outer Hebrides in unknown. However, two good population have been found; one from moss on wet rocks and one from semi-permanent rainwater pools in a disused quarry.

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