Valves are elliptic-lanceolate with flat faces and subrostrate apices. Valves are 7.8 to 13.4 µm in width. The central area on the raphe valve is large, symmetric, and transversely elliptic to rectangular. The raphe is straight to slightly sigmoid, with terminal fissures bent in opposite directions. The rapheless valve has a narrow sigmoid axial area and large hexagonal central area.