Stauroneis Circumborealis Guide
Credit: Loren Bahls
  1. Valves large, elliptic-lanceolate
  2. Apices short and broadly rounded
  3. Axial area 4-5 times wider than raphe
  4. Stauros wide
  5. Proximal raphe ends strongly curved

Stauroneis circumborealis has large elliptic-lanceolate valves with short, broadly rounded apices. The axial area is 4-5 times wider than the raphe and the stauros is wide. Proximal raphe ends are strongly curved.