Odontidium Mesodon Guide
Credit: Marina Potapova
  1. Valves elliptic-lanceolate with rounded ends
  2. Valves 6-12 µm wide
  3. Transapical costae 3-6 in 10 µm
  4. Rimoportula single, near apex

Valves elliptic-lanceolate, with rounded apices. Transapical striae and costae are visible in the light microscope.