FIGURES 96–101 in Observations on Hippodonta (Bacillariophyceae) in selected ancient lakes

FIGURES 96–101: SEM micrographs. Figs 96, 97. Hippodonta costulatiformis var. densistriata (type material). Fig. 96. External view of complete frustule showing narrow hyaline area present on valve mantle and the unornamented girdle. Fig. 97. Internal view of entire valve; striae positioned in shallow ridge depressions; interstriae strongly pronounced; helictoglossae in line with raphe slits. Figs 98–101. Hippodonta naviculiformis (type material). Figs 98, 100. External view of entire valve. Terminal pores of raphe deflected towards one valve side. Fig. 99. Internal view of entire valve. Lineolae positioned in shallow elliptical depressions. Central raphe endings simple linear and distantly positioned. Fig. 101. External view of broken frustule showing girdle unornamented. Scale bars in Fig. 96 = 2 µm; Fig. 97 = 5 µm; Figs 98–101 = 2 µm.