Genus: Cingulum (horizontal groove) located at the center of the body
(Illustrations of The Japanese Fresh-water Algae, 1977).
Cingulum more or less median; sulcus straight (Illrustrated Guide, 1985).
cell body 20 μm long, 17 μm wide,
x 640, Tanohara marsh, Shiga highland, Yamanouchi town, Nagano Pref., Japan, September 26, 2004 by Y. Tsukii
150 μm; x 400