FIGURES 12–17 in Two multi-stigmate Gomphonema species of Africa: Gomphonema kalahariense (nom. nov., stat. nov.) and Gomphonema chemeron (sp. nov.)

FIGURES 12–17. SEM images of Gomphonema kalahariense. Fig. 12. External valve view. "S" indicates position of stigmata. Fig. 13. Internal valve view. "S" indicates position of stigmta and "PS" indicates evident pseudoseptum. Figs 14, 15. External views. Fig. 14. Headpole. Fig. 15. Footpole. "APF" indicates position of apical pore field. Figs 16, 17. Internal views. Fig. 16. Footpole, showing the pseudoseptum. "H" indicates the helictoglossa. Fig. 17. Headpole, with both pseudoseptum and helictoglossa evident. Scale bars are indicated in the images.