Phylum: Charophyta   Family: Desmidiaceae

Cosmarium pseudobiremum f. minus Boldt

This is a misspelling by Boldt for C. pseudobireme but as it appears on Algaebase and other reference sites as such, I will leave it for now. The original diagnosis by Boldt was rather vague: ongoing research will address this issue in due course. A rare desmid found in oligo-mesotrophic water, but similar to other cells so misidentification is possible.

References: 
Boldt, R. (1888) Desmidieer Från Grönland
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium