Nupela Impexiformis Guide
Credit: Marina Potapova
  1. Valves elliptic-lanceolate with capitate ends
  2. Raphe absent on one valve
  3. Central area strongly asymmetric
  4. Striae not visible in LM

Valves are elliptic-lanceolate with capitate ends. Striae are radiate, but rarely discernible in LM. The central area is large, asymmetric and reaches the valve margin on one side of the valve. The raphe is absent on one of the valves.