Genus: Unicellular; planktonic; cell body tetrahedron in shape; each corner drawn out to form a projection;
many chloroplasts disc-shaped, without pyrenoids
(Guide book to the "Photomicrographs of the Freshwater Algae", 1998).
Similar genus -->> Tetraplektron;
Tetraedriella spinigera Skuja (or Teraedron regulare ?),
cell body 40 μm long, 40 μm wide,
x 640, Tane-ike (pond), Togakushi highland, Shinano town, Nagano Pref., Japan, June 12, 2005 by Y. Tsukii
94 μm; x 640