Nupela Decipiens Guide
Credit: Marina Potapova
  1. Valves lanceolate with acute apices
  2. Raphe valve with large central area
  3. Striae very fine
  4. Rapheless valve appears structureless

Valves lanceolate with acute apices. Nupela decipiens is heterovalvar; one valve has a raphe, one valve lacks a raphe. The axial area on the raphe valve widens into a broad, transversely rhomboid or diamond-shaped central area. The striae on the raphe valve are very fine, but can be resolved under LM. The rapheless valve usually appears nearly structureless under LM, because the striae are too fine to be resolved. Often, however, transapically elongated depressions are present on the external valve surface.