Cymbopleura Frequens Guide
Credit: Loren Bahls
  1. Valves lanceolate
  2. Apices apiculate to rostrate
  3. Central area reduced
  4. Apices straight, not tipped ventrally

Valves are lanceolate with apiculate to rostrate apices. The central area is greatly reduced, or absent. The apices are straight, rather than tipped toward the ventral margin.