Figs. 14-19. Prorocentrum formosum sp. nov. Fig. 14. The cell is ovate in left valve view. The surface is smooth and the anterior end flat. Fig. 15 The periflagellar area is located in the right valve, forming a broad, shallow depression. Fig. 16. The valve surface has large trichocyst pores (0.2 µm in diameter) distributed in a distinct pattern, and small pores (< 0.1 µm in diameter) around the cell periphery. Fig. 17. The cell surface is concave in side view. The surface of the apical area is smooth and has one flagellar pore. Fig. 18. The apical area at higher magnification showing a prominent curved apical collar (arrow) and an angled plate (arrowhead) adjacent to the flagellar pore (F) which is ornate with a flange. Fig. 19. The curved apical collar is the largest apical plate and has a height of 0.8 µm (arrowheads). It is situated opposite the angled plate (arrow).
Prorocentrum formosum holotype plate
EMu: Holotype SEM negative # 115099; SEM Stub # 115; Field # Lair muck #3 Accession # 407165; Catalog # 73; Figure # 5.
Figs. 20-21. Prorocentrum formosum sp. nov.Fig. 20. The intercalary band is transversely striated and wider in dividing cells. Fig. 21. Trichocyst pores are distributed in a characteristic pattern. They are round to oblong in shape with smooth edges, and equal size. The small pores are circular with smooth edges and distributed near the valve periphery.
EMu: Holotype SEM negative # 115099; SEM Stub # 115; Field # Lair muck #3 Accession # 407165; Catalog # 73; Figure # 5.
