Like the rest of this website, the glossary is a work in progress. If we’ve missed a term, please contact us to let us know the term and references.
A collum is the narrow, hyaline area at the edge of the valve mantle in the genus Aulacoseira.
The sulcus (a small furrow) separates the collum from the portion of the valve mantle with areolae.
See also ringleiste.