Mastogloia Calcarea Guide
Credit: Sylvia Lee
  1. Valve margins nearly parallel
  2. Apices rostrate
  3. Small central area, often asymmetric
  4. Raphe kinked near central area

Valves normally linear-lanceolate. Apices normally rostrate. Central area small, commonly asymmetric, elliptic to irregular in shape. Raphe generally straight, but kinked near the central area. Proximal raphe ends deflected in the same direction. Striae punctate, slightly radiate, becoming almost parallel near the apices.