Cymbopleura incerta has distinctly dorsiventral valves. Cymbopleura florentina has moderately dorsiventral valves and a wider axial area. Cymbopleura incertiformis var. laterostrata has linear-lanceolate valves and broadly protracted apices. Cymbopleura incertiformis var. linearis has linear valves with subrostrate to cuneate apices. Cymbopleura metzeltinii has rhombic-lanceolate valves.