Karayevia Pleonensis Gess Guide
Credit: Marina Potapova
  1. Valves 4.8-5.6 ┬Ám wide
  2. Valve ends subrostrate to rostrate
  3. Rapheless valve with hyaline lines
  4. Axial area lanceolate

Valves are elliptic-lanceolate with subrostrate to rostrate apices. Both raphe and rapheless valves have a lanceolate axial area and lack a distinct central area. Striae in the center of raphe valve are strongly radiate. On the rapheless valve they are are slightly radiate. Only on rapheless valve the striae are interrupted by a longitudinal hyaline line on each side of the valve.