FIGURES 19–23 in Morphology and phylogeny of Halamphora yongxingensis sp. nov. (Bacillariophyta), a new marine benthic diatom isolated from Yongxing Island, South China Sea

FIGURES 19–23. Halamphora yongxingensis sp. nov.,SEM micrographs. Fig. 19. Valve in internal view. Scale bar = 2 μm. Fig. 20. Central part of the valve in internal view. Note the proximal raphe ends terminate at a tongue-like expansion, the continuous striae on the ventral side of the valve (arrow a). A single row of elongated areolae close to the raphe-sternum is delimited by an internal longitudinal rib (arrow b) and not interrupted at the centre. Scale bar = 1 μm. Fig. 21. Valve apex in internal view showing distal raphe ending at a poorly developed helictoglossa (arrow). Scale bar = 1 μm. Fig. 22. Girdle bands on dorsal side of the frustule composed of two rows of ovoid or round poroids. Scale bar = 2 μm.