Plate 37

Description:

Plate 37. Prorocentrum arenarium. Figs. 1-5. SEM. Fig. 1. Right valve: cells round to ovoid. Periflagellar area is a broad, V-shaped depression. Short longitudinal flagellum visible (arrowhead). Marginal poroids present (arrows). Fig. 2. Left valve: surface smooth, with scattered valve and marginal poroids (arrows). Fig. 3. Lateral view: intercalary band smooth; marginal poroids evenly spaced (arrowheads). Fig.4. Marginal poroids oblong to kidney-shaped. Fig. 5. Periflagellar area: triangular and unornamented with large flagellar pore (f) and smaller auxiliary pore (a). Fig. 6. LM. Right valve: posterior nucleus (n) and prominent central pyrenoid (arrow).