Phylum: Charophyta   Family: Desmidiacea

Cosmarium pseudogoniodes P.F.M. Coesel & K.J. Meesters 2023

A small cell with a very shallow sinus that is wide open. Semicell sides are slightly convex and merge smoothly with the apex, which can be slightly convex to truncate. Apical view is circular.
Single cell dimensions: L: 16.7 µm, B: 8.9 µm, Is: 7-3 µm; L/B: 1.88.
In Europe this small taxon is regarded as widely distributed in acidic oligo-mesotrophic habitats. It was first recorded in the Outer Hebrides in 2023 but could easily be overlooked due to its small size.

References: 
Coesel, P.F.M. & Meesters, K.J. (2023 second edition). Desmids of the Lowlands.
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium. Part 1: Text. Part 2: Plates.
Van Westen, M. (2024). Sieralgen in Drenthe.