Neidium Densestriatum2 Guide
  1. Valves elliptic
  2. Proximal raphe ends straight
  3. Central area transveresly elliptic
  4. Longitudinal canals present

Valves are elliptic. The proximal raphe ends are distinctly straight. The central area is transversely elliptic. Longitudinal canals are present on the valve margin.