FIGURES 17–21 in The diatom genus Ctenophora: A discussion on its morphology, relationships, and some species

FIGURES 17–21: Ctenophora pulchella (Ralfs, BM herb.). SEM micrographs, Fig. 17, internal view of entire valve with VC at one side; Fig. 18, detail of pole, internal view showing rimoportula, virgae, vimines and sternum; Fig. 19, detail of central with enlarged (or modified) and (in this specimen) a vague appearance of 'ghost striae'; Fig. 20, entire VC; Fig. 21, detail of 2nd (?) band (copula) with 'areola'–like ornamentation along its length. Scale bars = 2μm (Figs 18, 19, 21), 10μm (Figs 17, 20).