FIGURES 22–27 in Prestauroneis genkalii-a new diatom species (Bacillariophyceae: Stauroneidaceae) from Southeast Asia

FIGURES 22–27: Prestauroneis genkalii Glushchenko, Kulikovskiy & Kociolek, sp. nov. SEM. External view (Figs 22–24), internal view (Figs 25–27). Figs 22: Whole valve, raphe filiform, proximal raphe endings are slightly expanded, weakly unilaterally curved, distal raphe fissures unilaterally curved in opposite way to proximal ends. Fig. 23: Central area, proximal raphe ends, openings of areolae are variable in shape and orientation, rounded to elliptic. Fig. 24: Distal raphe fissure. Fig. 25. Raphe filiform, helictoglossae are small, the raphe located on weakly pronounced sternum-like structure, pseudoseptae are present on the mantle of each valve apex. Fig. 26: Central area, proximal raphe endings indistinct and sometimes hook-like, openings of areolae round, occluded by hymenes. Fig. 27: Pseudosepta present, openings of areolae round, occluded by hymenes. Scale bars = 5 μm (Figs 22, 25); 1 μm (Figs 23, 24, 26, 27).