PLATE 13 in The diatom genus Gomphoneis Cleve (Bacillariophyceae) from Lake Baikal, Russia

PLATE 13: SEM. Gomphoneis tumida. Figs 382–387: Fig. 382: External valve view. Arcuate raphe has dilated proximal ends and deflects onto the mantle at the poles. Striae are composed of round areolae in two rows. Figs 383–387: Internal valve views. Fig. 383: Full valve view showing rounded central area and prominent pseudosepta at the poles. Fig 385: Specimen without girdle bands shows septa at the poles and the large helictoglossae. Fig. 386: View of valve from central area to footpole, showing narrow axial area, and robust striae and interstriae. Septum is evident at footpole. Fig. 384: Central area showing the proximal raphe ends recurved in the same direction and rounded to ellipsoidal stigma openings occluded by teeth-like projections. Fig. 387: Central area showing the inwardly raised central nodule, with the stigmoids in depressions around the base and the elevated raphe ends recurved at its margin. G. sublanceolata. Fig. 388: External valve view shows the dilated proximal raphe ends, simple, rounded stigmoidal openings and striae composed of rounded, unoccluded areolae. The striae terminate with a single areola along the length of the valve.