Psammothidium Rossii2 Guide
  1. Ends slightly protracted
  2. Valves bent
  3. Central area on raphe valve a narrow rectangular
  4. Central area on rapheless valve lanceolate

Valves are elliptic-lanceolate with slightly protracted ends. The valves are distinctively flexed. On the raphe valve, the central area is narrowly rectangular. On the rapheless valve the central area is lanceolate.