Surirella Tenera Guide
Credit: Tahmineh Rouzbahani
  1. Valves large, heteropolar
  2. Porcae regularly spaced
  3. Central hyaline line narrow
  4. Fenestrae large

Valves are large and heteropolar, with a rounded headpole and cuneate footpole. Porcae, or transapical undulations, are regularly spaced, 18-26 in 100 ┬Ám. A narrow-lanceolate hyaline axial area is present. Fenestrae are large and conspicuous.