Rhoicoshenia Californica Guide
Credit: Evan Thomas
  1. Apices protracted
  2. Valves narrow
  3. Axial area narrow
  4. Central area oval

Valves are linear-lanceolate and heterovalvar. The valves are narrow, 3-6 ┬Ám wide.The axial area is narrow on both the raphe and reduced raphe valves. The central area is small and ovate. Proximal raphe ends are relatively close together on the raphe valve. The apices are protracted, especially in larger specimens. The striae are lineate, rather than distinctly punctate.