Genus: Cell body elongated spindle in shape, straight or curved, sharply pointed at both ends; (Guide book to the "Photomicrographs of the Freshwater Algae", 1998). Species: Cell body elongated fusiform, tapering toward sharply pointed ends, 40-68 μm long, 2 μm wide; two chloroplasts parietal, extending into the both ends, without pyrenoids; cell division produces 2, 4, 8 or 16 "autospores" (Photomicrographs of the Freshwater Algae, 1996).

50 μm 100 μm 150 μm; x 400

Monoraphidium griffithii ?, x 400, by Y. Tsukii