Valves are lanceolate with rounded or very slightly drawn-out ends. The proximal raphe ends are straight and slightly expanded. The central area is transversely elliptical or irregular-rectangular, often slightly asymmetric. The lineolate striae are radiate, becoming convergent at the valve apices, 12-13 in 10 µm. The areolae are easily observed under LM and number 28-32 in 10 µm.