Stauroneis Rex Guide
Credit: Loren Bahls
  1. Valves very large
  2. Striae coarse, 12-14 in 10 µm
  3. Proximal raphe ends straight
  4. Apices bluntly rounded

Stauroneis rex is huge: 36-60 µm wide and 215-386 µm long. Valves are lanceolate with bluntly rounded apices. Proximal raphe ends are straight. Striae are coarse and number 12-14 in 10 µm.