Visit us at

Diatoms of the United States is now known as Diatoms of North America.
This site has been redesigned and updated, and will be closing soon.

Raphe ledge



Rapheless valve

A thin, elevated structure, with the shape of the letter T, that extends along the lateral side of the raphe.

Compared to a conopeum, a raphe ledge is more elevated, more narrow, and does not cover part of the valve face. Common in the genus Amphora and closely related genera.