Phylum: Charophyta   Family: Desmidiaceae

Cosmarium contractum var. incrassatum K. Förster 1981

First described by Förster (1965: 134, pl. 3: 13, & pl. 10: 20 [ICN invalid]), validation in Förster (1981: 227). It was later moved by Scharf (1981: 42) to C. moniliforme var. subglobosum, where most recent records will be found. However, this association with moniliforme is not shared by Kouwets (in manuscript).
Cell dimensions: L. 36-40 µm; B. 19-22 µm; Is. 8-10 µm; Th. 18-19 µm; L/B. 1.8-1.9.
It would seem a genuinely rare taxon found in oligotrophic waters in the benthic layer.

References: 
Förster, K. (1965). Beitrag zur Desmidieen-Flora der Torne-Lappmark in Schwedisch-Lappland.
Förster, K. (1981). Revision und Validierung von Desmidiaceen-Namen aus früheren Publikationen: 1.
Kouwets, F.A.C. (in manuscript). European Flora of the Desmid Genus Cosmarium.
Scharf, W. (1977). Zieralgen aus dem arktischen Norwegen.