Compare

Campylodiscus noricus has more numerous radial ridges (~20-30 in 100 µm).

LM scalebar = 10 µm
Campylodiscus4 Campylodiscus7 Campylodiscus6 Campylodiscus1 Campylodiscus3 Campylodiscus2 Campylodiscus5
Length Range
70-114 (greatest valve dimension) µm

Also compare to

Campylodiscus noricus

Ehrenb.