Brevilinea Iconic
  1. Frustules extremely small
  2. Raphe reduced

Frustules are extremely small, less than 15 ┬Ám in length. Valves are broadly lanceolate, with small, capitate apices. The raphe is linear and short. The raphe is contained within a distinctly thickened sternum. Striae are slightly radiate in the center valve, becoming parallel near apices. Striae are composed of single row of 1-2 areolae, a feature visible in SEM. Externally, the proximal and distal raphe fissures are slightly deflected to the same side of the valve. The distal raphe terminates in a small poroid.

The genus Brevilinea is monotypic. The single species, Brevilinea pocosinensis, is known only from Pungo Lake, an acidic, poorly buffered lake, high in dissolved humic acids in the southeastern U.S.