Cosmarium tutum Shyndanovina
Cosmarium tutum in Phytotaxa 461(4): 244. 9 Oct 20201
is new name for Cosmarium perforatum var. skujae in Memoranda Soc. Fauna Fl. Fenn. 21: 56. 1945
Cosmarium tutum
1. Cosmarium perforatum var. rotundatum Skuja 1928, nom. illeg. was given as the replaced synonym in Shyndanovina (2020: 244).