Section [ Actinotaenium ]:
Cell body cylindrical, slightly constricted at the center, cell surface smooth or dotted or punctated
(Illustrations of The Japanese Fresh-water Algae, 1977).
Species:
Cell body small, 22-(32-43)-60 μm long, 10.5-(20-23)-32 μm wide,
isthmus 9.5-(18-21.5)-30 μm wide, L/W=2; semicells ovoidal;
(Illustrations of the Japanese Fresh-water Algae, 1977).
Cosmarium curtum (Brébisson) Ralfs ??,
cell body 40-43 μm long, 19-21 μm wide, isthmus 17-20 μm wide,
x 640, standing water near Tama river, Chofu city, Tokyo, Japan, February 24, 2004 by Y. Tsukii
31 μm
63 μm
94 μm; x 640
Cosmarium curtum (Brébisson) Ralfs:
Cell body small, 22-(32-43)-60 μm long, 10.5-(20-23)-32 μm wide,
isthmus 9.5-(18-21.5)-30 μm wide, L/W=2; semicells ovoidal;
(Illustrations of the Japanese Fresh-water Algae, 1977).