[1] (Original description) The shell has a small, blunt nucleus of one or two whorls.

The columella is solid, with one strong, nearly horizontal plait continuous upon the whole axis.

Type Borsonia dalli There is never more than one plait in Borsonella ; in Cordieria Rouault, 1848, as restricted by Cossmann, there are never less than two.

In Rouaultia the anal sulcus is narrow, sharp, and situated at the shoulder in the peripheral carina.

Both Cordieria and typical Borsonia have a long and slender canal and the general aspect of Gemmula Weinkauff, 1875, while Borsonella resembles an Antiplanes Dall, 1902 with a strong plait on the proximal part of the columella.