Melosira dendrophila has spines grouped in marginal clusters, separated by porefields. Orthoseira johansenii has a larger central area with fine, weakly organized striae and spines separated by 2-4 striae.
LM scalebar = 10 µm
Diameter
22.1-50.5 µm
Striae in 10 µm
6.4-7.1 based on circumferential density