P Daonensis Guide Copy
Credit: Marina Potapova
  1. Valves elliptical to linear-elliptical
  2. Central area on rapheless valve rhomboid with irregular edges
  3. Raphe straight

Valves are elliptical to linear-elliptical. The raphe valve has a linear axial area, which widens into a transapically elliptical, rectangular, or diamond-shaped central area. The raphe is straight without terminal raphe fissures. The rapheless valve has a large rhomboid axial area with an irregular border. The striae are radiate, 24-30 in 10 ┬Ám.