Geissleria Lateropunctata Guide Copy
Credit: Marina Potapova
  1. Valves elliptical-lanceolate with narrowly rostrate or subrostrate apices
  2. Central area formed by one shortened stria at each side
  3. One to five isolated areolae in central area
  4. Annulae in three or four rows at poles

Valves are elliptical-lanceolate, often slightly dorsiventral, with narrowly rostrate or subrostrate ends, 7.0-9.0 µm wide and 15-25 µm long. The central area is small, with one to five isolated areolae. Striae are radiate, and number 18-22 in 10 µm. The annulae form three-four rows at each pole.