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Guide to Psammothidium pennsylvanicum

Potapova 2012

Psammothidium Pennsylvanicum Guide
Credit: Marina Potapova
  1. Valves small, elliptic
  2. Striae 25-29 in 10 μm
  3. Areolae 35-40 in 10 μm
  4. Rapheless valve with strongly asymmetric central area

Valves are elliptic. The raphe valve has a narrow linear axial area and transversely rectangular, or elliptic central area. The raphe is straight. The rapheless valve has a narrow linear axial area and an asymmetric central area. Areolae number 35–40 in 10 μm within each stria.