Cells are joined into chains that are slightly twisted about the central axis. Cells are rectangular with slightly rounded corners, not touching at the corners. Valves are slightly convex. The apertures are wide and elliptical with a slight constriction in the middle. Setae originate inside the malve margin, cross at the chain edge and and are generally perpendicular to the chain axis. Terminal setae diverge at a wide angle.
Resting spores have evenly vaulted primary valves with 2-12 dichotomously branched spines. The secondary valve is smooth and inflated