FIGURES 168–173 in Novel diatom species (Bacillariophyta) from the freshwater discharge site of Laguna Diablas (Island Isabela = Albemarle) from the Galapagos

FIGURES 168–173: Pinnularia valdecontroversa sp. nov. SEM external views. Fig. 168: raphe fissure slightly wavy (arrow), proximal ends weakly expanded (arrowhead). Figs 169, 171-173: terminal raphe fissure indistinctly curved and sickle-shaped (arrow in Fig.169). Fig. 170: frustule in girdle view. Note the terminal raphe end (arrow). Fig. 171: discontinuity between subdistal and circumpolar striae resulting in a gap (arrow). Note the presence in external view of the open alveola covered with porous membranes (arrow in Fig.173).