Diploneis puellafallax guide
  1. Axial area narrow, linear
  2. Valve width 11-13 µm
  3. Striae radiate
  4. Striae biseriate
  5. Longitudinal canal with two rows of areolae

Valves are elliptic to linear elliptic with bluntly rounded apices. Valve width is 11-13 µm. Axial area is narrow and linear, expanding toward an elliptic central area. Longitudinal canal is lanceolate, with two rows of areolae. Striae are radiate and biseriate.