FIGURES 18–23 in New Amphicocconeis (Bacillariophyta) from Raivavae and Tahiti Islands (South Pacific) and Porto Belo (Brazil), with re-examination of Psammococconeis

FIGURES 18–23. Amphicocconeis clypeus sp. nov. SEM (material 'Papeete 4 Holothuria', from Tahiti, South Pacific). SV in external view with still partly connected SVVC in advalvar view (Fig. 18), note the marginal row of dense areolae. SV in oblique view, with a SV sternum slightly convex, with four copulae (Fig. 19), SVVC open, with large pores, abvalvar view (Figs 21–22), SV areolae in external view, with 'sepia-like' opening (Fig. 20), SV in internal view with areolae covered by convex hymenes (Fig. 23). Scale bars: 6 µm (Fig. 22), 5 µm (Fig. 18), 4 µm (Fig. 23), 3 µm (Fig. 19), 1 µm (Fig. 21), 600 nm (Fig. 20).