Cymbella Affinis Guide
Credit: Marina Potapova
  1. Valves strongly dorsiventral
  2. Valves 6.9-9.0 μm wide
  3. Central area indistinct
  4. Stigma one
  5. Areolae 25-30 in 10 μm

Valves are strongly dorsiventral, with subrostrate to rostrate apices. The dorsal margin is strongly arched, whereas the ventral margin is slightly convex or flat, often excised. The central area is very small or indistinct. One stigma is present at the end of the middle striae. The areolae number 25-30 in 10 μm.