Plate 21

Description :

Plate 21. Gonyaulax polygramma. Figs. 1-3. SEM. Fig. 1. Ventral view: cell large, elongate and quadrilateral. Epitheca with prominent apical horn (arrow). Cingulum left-handed, displaced 1.5 X its width; sulcus widens posteriorly. Longitudinal ridges on thecal surface with reticulations in between. Fig. 2. Lateral ventral view: transverse (TF) and longitudinal (LF) flagella present. One antapical spine (arrow). Fig. 3. Dorsal view: hypotheca truncate with straight sides. Three antapical spines (arrows): one large and two small. Figs. 4-5. LM. Fig. 4. Ventral view: reticulations evident; one long antapical spine (arrow). Fig. 5. Dorsal view: prominent longitudinal ridges. Fig. 6. Line drawing.