Cymbella Proxima F Gravida Guide
Credit: Marina Potapova
  1. Valves with broad, rounded apices
  2. Ventral valve margin slightly concave with slightly tumid center
  3. Central area circular
  4. Stigmata 3-4
  5. Raphe lateral, filiform at distal and proximal ends

Valves are strongly dorsiventral, with broad rounded apices, 18-23 µm wide. The dorsal margin is strongly arched, whereas the ventral margin is slightly concave, but with a slightly tumid central portion. The central area is circular with 3-4 stigmata. The raphe is lateral near the middle of the valve, becoming filiform near the distal and proximal ends. Striae are radiate. Areolae number 14-16 in 10 µm.