FIGURES 13–18 in Navicula amoyensis sp. nov. (Bacillariophyceae), a new benthic brackish diatom species from the Jiulong River estuary, Southern China

FIGURES 13–18. SEM micrographs of Navicula amoyensis sp. nov. Figs 13, 14. Internal views of entire valves of different frustules, showing an additional lateral thickening at the centre of the accessory rib (arrow). Fig. 15. Internal valve view showing details of central raphe fissures with a distinct central interruption (arrow). Fig. 16. Internal view showing details of the valve apices, where linear raphe axis distally terminated by more or less rounded helictoglossa (arrow) and positioned just below the terminal area. Fig. 17. Internal view. Striae composed of simple slit-like lineolae, positioned in shallow and narrow depressions (arrow). Fig. 18. Internal central raphe endings, interrupted by an extended thickening accessory rib (arrow). Scale bars in figs 13, 14 = 5 μm; fig. 15 = 2μm; figs 16–18 = 1 μm.