Solitary cells or joined in long, usually straight colonies. In girdle view the frustule is cylindrical, while in valve view it appears roughly circular. Each valve has a ring of fultoportulae with elongated external processes that enable the union of two adjacent cells and the exchange of cytoplasm between them. In addition the union can take place in two ways: either a process of one cell joins with a process of another cell (1:1 linkage) or a process of one cell joins two processes of another cell (1:2 linkage). Both on the valve surface and on the mantle there may occasionally be rimoportulae. In the cytoplasm there are one or more discoid chloroplasts per cell and a central nucleus.

Marine genus.

Descriptions of new and rare diatoms., Series XVI . Transactions of the Microscopical Society, New Series, London 13:, Greville R.K., 1865, 43-57