Genus: cell body flat, constricted at the center; semicell ellipsoidal or subtriangular, central area of the apex slightly elevated, cells connected with each other at their central area of apex forming filament. Species: Cell body 25-38 μm long, 20-26 μm wide; constriction 7-10 μm; indentation widely opened and rounded the the extremity; semicells subtriangular with broadly rounded margins; vertical view of semicells triangular with broadly rounded angles and sides strongly concave; filaments not twisted (Phtomicrographs of the Fresh-water Algae, vol.3, 1985)

31 μm 63 μm 94 μm; x 640