Species within the Eunotia praerupta - Eunotia bidens group also possess slight dorsal undulations.
Eunotia inflata has a rounded dorsal margin.
Eunotia superbidens has dorsally recurved ends.
Eunotia richbuttensis valves are more narrow and consistently possess one apical rimoportula.
BioData Reference
Krammer and Lange-Bertalot 2/3 Pl 148 Fig 1-3