FIGURES 26–32 in Four new Pinnularia Ehrenberg (Bacillariophyta, Pinnulariaceae) species from Amazonian black water (Tupé Lake, Amazonas State, Brazil)

FIGURES 26–32. SEM: Pinnularia tupensis sp. nov. Fig. 26. General internal view of valve. Fig. 27. Ends showing terminal raphe with a prominent helictoglossa (arrow). Fig. 28. Internally, proximal raphe fissure showing no intermission near central nodule. Fig. 29. External view showing proximal raphe fissures bent in same direction. Fig. 30. Ends capitate, elongate. Figs 31, 32. Detail of alveoli structure and bayonet raphe shape. Scale bars: Figs 26, 28, 30 = 5 µm; Figs 29, 31 = 2 µm; Figs 27, 32 = 1 µm.