Sellaphora Rexii Guide
Credit: Marina Potapova
  1. Valves elliptic with subrostrate apices
  2. Grooves along each side of raphe 0.5 μm wide
  3. Grooves covered by conopea
  4. Central area transversely rectangular or bow-tie shaped

Valves are elliptic, with subrostrate apices. Valves are 22-33 μm long and 7.1-8.6 μm wide. The axial area is linear, formed by grooves, one at each side of the raphe. Grooves are approximately 0.5 μm wide and covered externally by non-porous conopeum. Grooves and conopea are interrupted by the central area, which is transversely rectangular, or bow-tie-shaped and bordered by striae of an irregular length. Polar bars are present.