Forms straight or slightly curved ribbon-shaped colonies in girdle view. Each cell has two chloroplasts located along the girdle. In girdle view, cells are low and rectangular. The valves are linear with parallel margins and rounded ends, have an eccentric raphe, no central nodule and approximately the same number of striae and fibulae. Interstriae are parallel except at the poles.
Apical axis 4.5-74 µm, transapical axis 2.4-4 µm, 12-18 striae and fibulae in 10 µm.
Throndsen, J., Hasle, G.R. and Tangen, K., 2007. Phytoplankton of Norwegian coastal waters. Almater Forlag AS. 341 pp.