Cymbella Mexicana Kamc Guide
Credit: Loren Bahls
  1. Valves relatively broad
  2. Apices weakly protracted, bluntly rounded
  3. Minimum valve length ~64 µm
  4. Single large stigma

Valves are relatively broad, with a strongly arched dorsal margin and a weakly convex to nearly flat ventral margin. The apices are bluntly rounded and weakly protracted. Minimum valve length is about 64 µm. A single large stigma is present between the proximal raphe ends.