Scale bar = 10µm

In girdle view frustules are bent (image on right), so that in valve view one valve is concave and one is convex. On the convex valve, raphe extend to the valve center, and central area is small and oval to elliptic (not pictured). On concave valve, raphe are significantly shortened and end close to the apices; central area is absent (center image). Striae are 12-14 per 10µm. Internally, a pseudoseptum is present at both apices (image on left). Apical pore field is present at footpole, and cells grow on mucilage stalks.