Cosmarium crenatum fo. Ralfs
Reference: Nordstedt 1872
Synonym: ?Cosmarium ordinatum E. Larsen (nom. illeg.)
Compare with: Cosmarium cf. crenatum; Cosmarium costatum var. gutwinskii
Remarks: The specimen depicted below are in literature often classified as Cosmarium crenatum. The outline of the cells differs from to the original figures of Ralfs and match better with two forms described by Nordstedt as Cosmarium crenatum «Crenae laterales 2» and «Crenae laterales 3» from Svalbard and must be provided with a new taxonomic name. This taxon has three crenations on each side of the semicell and four at the apex. Sometimes a small granule is visible at the basal corner.
C0667
2010011001
C0667
2019041001
C0667
2019041001
2010011-001
Front view
Netherlands
2019041-001
Front view
Netherlands
2019041-001
Side view
Netherlands
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