Genus: Unicellular, planktonic; cell body flat tri- or quadrangular in shape, with hairy projections at each point;
a single chloroplast plate-like in shape, with a pyrenoid
(Illustrations of The Japanese Fresh-water Algae, 1977).
Species: Cell body polygonal, wtih 2-3 spiny projections at each corner, 12-15 μm in diam., spines 10-15 μm long; a chloroplast plate-like, with a single pyrenoid (Illustrations of The Japanese Fresh-water Algae, 1977).
Images of collecting locality:
Showa-machi general park, Showa town, Saitama Pref., Japan, February 12, 2006 by Y. Tsukii