Family [ Chlamydomonadaceae ]: Unicells; cell wall present; two flagella (Illustrations of The Japanese Fresh-water Algae, 1977).
Genus (Ehrenberg): Cells usually fusiform; both ends hyaline; two euqal-length flagella, about 1/2 as long as cell; eye spot present in most species; two or several contractile vacuoles; trasverse division to form 4 zoospores; nutrition phototrophic or chemo-organotrophic (Illustrated Guide, 1985).

C. euchlorum ? 4 clips μm dividing cells Japan, 1998