Navicula Rhynchocephala Guide
Credit: Pat Kociolek
  1. Valves lanceolate
  2. Apices elongate-protracted, rounded
  3. Central striae widely spaced
  4. Striae distinctly lineate

Valves are lanceolate with elongate-protracted, rounded apices. The axial area is narrow, straight, widening to form an irregularly-rounded to elliptical central area. The central area formed by shortened striae that are also more widely spaced than elsewhere on the valve. The striae are distinctly lineate, radiate around the center, becoming parallel, then convergent at the ends.