Genus: Cell body short, radiate in shape; apical view of the cell, triangular, polygonal,
ellipsoidal or spindle-shaped; zygospores formed outside of mother cells
(Illustrations of The Japanese Fresh-water Algae, 1977).
Similar genus -->> Tetraedriella (Xanthophyceae);
Tetraedron limneticum Borge ?,
cell body μm long, μm wide,
x 640, O-ike (pond), O-ike park, Yabuki town, Fukushima Pref., Japan, August 2003, by Y. Tsukii
94 μm; x 640