Valve linear, with triundulate to almost parallel sides. Ends broadly capitate, blunt or flatly rounded. Raphe slightly filiform, small central pores. Ends of fissures distinctly question mark shaped. Axial area narrow and linear. Fascia of varied breadth, small and round. Striae parallel to radial end, slightly to strongly bent, crossed by the marginalband(Krammer and Lange-Bertalot (2/1) 1986).