Genus: Filament without branching; cell body cylindrical; each cell wall consists of two parts with "H" structure overlapping at the midregion; chloroplasts many, disc-shaped, without pyrenoids (Guide book to the "Photomicrographs of the Freshwater Algae", 1998). Species: Filament 4-5 μm wide; cell body 15-50 μm long (Süßwasserflora von Mitteleuropa 3, Xanthophyceae 1, 1978).

50 μm 100 μm 150 μm; x 400 :

31 μm 63 μm 94 μm; x 640