Phylum: Charophyta   Family: Desmidiaceae

Cosmarium magnificum var. italicum Raciborski 1889

This variety differs from the nominate in the less well developed central swelling and with slightly smaller dimensions. In the cell found from Lewis, the central portion is little more than cell-wall thickening. See Couté & Tell (1981, p. 86, pl. 24: 1-6) for SEM images. A rare taxon found in oligo-mesotrophic waters.

References: 
Raciborski, M. (1889) Nowe Desmidyje.
Couté, A. & Tell, G. (1981) Ultrastructure de la paroi cellulaire des Desmidiacées au microscope électronique à balayage.
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium.