Valves of B. wygaschii are more rhombic in valve outline than B. neoactuta, with a large central area and a lower stria density (20-24 in 10 µm). Valves of B. metzeltinii are more narrow and shorter in length (26-37 µm) and have a higher stria density (27-30 in 10 µm). Brachysira liliana valves have a higher density of stria and areolae, along with a longitudinally expanded central area.