Genus: Unicellular, planktonic; cell body elongated spindle-shaped, spirally twisted;
both ends drawn out as spiny projections; a single chloroplast plate-like in shape, with a pyrenoid
(Guide book to the "Photomicrographs of the Freshwater Algae", 1998).
cell body spiral, 37 μm long,
x 400, x 640,
Kurome River, Asaka City, Saitama Pref., September 2000, by Y. Tsukii