Valves are strongly dorsiventral with acuminate rounded apices, 18-23 µm wide. The ventral margin is tumid in the middle. The central area is circular with 2-5 stigmata. The raphe is lateral near the middle of the valve, becoming filiform near the distal and proximal ends. Striae are radiate, 7-8 in 10 µm. Areolae number 14-16 in 10 µm.