Eunotia horstii valves are similar to E. gracillima valves, except that the valves of E. horstii are more broad and have a higher stria density. Eunotia horstii valves have similar measurements to E. groenlandica, but these species differ by the shape of the valve ends. The ends of E. horstii are more recurved than those of E. groenlandica. Eunotia horstii is also similar to E. fallax, but the striae of E. horstii are evenly spaced relative to those of E. fallax, especially in the central area of the valve.

LM scalebar = 10 µm
Eunotia horstii LM3 Eunotia horstii LM1 Eunotia horstii LM6 Eunotia horstii LM5 Eunotia horstii LM2 Eunotia horstii LM4
Length Range
18-33 µm
Width Range
2.8-3.3 µm
Striae in 10 µm
13-17 in the valve center, 18-22 at the ends, areolae unresolved in LM

Also compare to

Eunotia gracillima

(Krasske) Nörpel-Schempp

Eunotia fallax


Eunotia groenlandica

(Grunow) Nörpel-Schempp and Lange-Bert.