Genus: Unicellular; planktonic; cell body elongated cylindroid, curved or twisted; both ends rounded, with spiny projections;
cell wall not separated into two parts (compare to Centritractus);
several chloroplasts plate-like, without pyrenoids
(Guide book to the "Photomicrographs of the Freshwater Algae", 1998).
Images of collecting locality:
Standing water near Suga-daira marsh, Ueda city, Nagano Pref., Japan, July 6, 2006 by Y. Tsukii