Psammodictyon roridum

Nitzschia rorida M.H.Giffen 1975 has always been one of the very few easily recognizable and identifiable Nitzschias in my samples. The problem is, I somehow missed the fact that it's no longer a Nitzschia. It became Psammodictyon roridum (M.H.Giffen) D.G.Mann 1990 years ago, and the change was made in The Diatoms: Biology and Morphology of the Genera, no less. Surprisingly, it's called Nitzschia in some of the new guides, so I guess I wasn't the only one to miss the new name. And the change is well justified! Anything with any distinct features shouldn't belong to Nitzschia! All Nitzschias look the same!