Navicula Oppugnata Guide
Credit: Loren Bahls
  1. Valves lanceolate
  2. Proximal raphe ends bent to secondary side
  3. Striae coarse
  4. Areolae coarse

Navicula oppugnata has lanceolate valves, wider than 8 µm. Proximal raphe ends are bent to the secondary side of the valve. Striae are coarse and number 9-11 in 10 µm. Arolae are also coarse, easily resolved in LM and number 24-26 in 10 µm.