Brachysira Microcephala
Credit: Paul Hamilton
  1. Valves with subcapitate to capitate apices
  2. Central striae radiate
  3. Central area small, asymmetrically rounded
  4. Areola shape variable

Valves are lanceolate to rhombic-lanceolate with protracted, subcapitate to capitate apices. The central striae are radiate at the center, to parallel at the apices. Areolae are variable in shape and arranged in a series of two to three longitudinal hyaline zones. The central area is small and asymmetrically rounded.