Species within the Eunotia praerupta - Eunotia bidens group also possess slight dorsal undulations and should be compared with E. richbuttensis. The two dorsal undulations of E. richbuttensis distinguish it from the rounded dorsal margin of E. inflata. Eunotia superbidens valves have dorsally recurved ends, in comparsion to the round, or flat ends, that are not recurved toward the dorsal margin in E. richbuttensis. Eunotia richbuttensis valves are more narrow and consistently possess one apical rimoportula, in contrast with the wider valves of E. bidens, where rimportulae are lacking.

LM scalebar = 10 µm
Eunotia richbuttensis LM1 Eunotia richbuttensis LM2 Eunotia richbuttensis LM3 Eunotia richbuttensis LM4 Eunotia richbuttensis LM5 Eunotia richbuttensis LM6
Length Range
20-59 µm
Width Range
7.3-9.9 µm
Striae in 10 µm
10-14 at the center of the valve, 12-16 at the ends

Also compare to

Eunotia praerupta


Eunotia bidens


Eunotia superbidens


Eunotia inflata

(Grunow) Nörpel-Schempp and Lange Bert.