Valves are linear-lanceolate with broadly subrostrate ends. Striae are slightly radiate throughout the valve, parallel or slightly convergent at the apices, 34-38 in 10 μm. Raphe is absent on one of the valves. Raphe valve has rhombic-lanceolate axial area and round central area. Rapheless valve has rhombic-lanceolate axial area, but no distinct central area.