FIGURES 36‒41 in Two new Stauroneis species (Bacillariophyta, Stauroneidaceae) from midwestern karstic Brazilian formations

FIGURES 36‒41. Stauroneis karstica Tusset, Tremarin & T. Ludwig sp. nov. Figs 36‒40. SEM. Fig. 41. TEM. Fig. 36. External view of valve. Fig. 37. External view of median region showing the proximal raphe endings and striation pattern. Fig. 38. Internal view of median region of valve showing the stauros and proximal raphe endings. Fig. 39. Tilted valve showing the distal raphe ending extending to the mantle. Fig. 40. Internal view of valve apex, note the helictoglossa and pseudosepta. Fig. 41. Detail of areolae occlusion near the apex. Scale bars = 5 μm (Fig. 36), 2 μm (Figs 39, 40), 1 μm (Figs 37, 38), 0.5 μm (Fig. 41).