Cymbella subcistula has a nearly filiform raphe, 2-5 stigmata and areola density of 19-24 in 10 µm. Cymbella dorsenotata has up to 6 stigmata, a cymbiform to lunate outline, and coarser areola density of 12-15 in 10 µm. Cymbella proxima has broader valves and lower areola density (12-15 in 10 µm). Cymbella blinni has smaller valves (<12 μm wide), higher areola density (22-30 in 10 μm), higher stria density (10-15 in 10 μm) and 1-5 stigmata.