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).
Species: Cell body with a short projection at one end; terminus of the projection slightly swelled; daughter cells attached at opposite end of their mother cell (Illustrations of Japanese fresh-water algae, 1977).