Stauroneis circumborealis has wider axial and central areas and proximal raphe ends that are more strongly inflated and curved. Stauroneis gracilis and S. supergracilis have narrower valves in proportion to their length. Stauroneis phoenicenteron and S. rex have straight, rather than curved, proximal raphe ends. Stauroneis sonyae has elliptic- or rhombic-lanceolate valves and a very wide stauros, often with numerous short striae.