Genus: Colony of 4 cells attached to a gelatinous sheath at their posterior end, arranging cruciform; cell body ovoidal; two equal-length flagella emerging at their anterior end; a single chloroplast cup-shaped, with a pyrenoid (Guide book to the "Photomicrographs of the Freshwater Algae", 1998). Species:

31 μm 63 μm 94 μm; x 640

Images of collecting locality: Iruma Park, Koyo-dai, Iruma city, Saitama Pref., Japan, March 18, 2006 by Y. Tsukii