Eunotia canicula is similar to E. incisa and the size range of the two species overlap. The apices of E. incisa, however, are more inset (more like a snout, or nose) than the apices of E. canicula. Furthermore, the valves of E. canicula are more narrow and the helicotoglossae are closer to the apex (less inset) as compared to E. incisa.