FIGURES – 7. SEM images of Craspedostauros laevissimus from different populations. 42. Close up of the central area externally, showing the weakly expanded central raphe endings and the cribrate areolae with usually four to five peripheral pores and up to one central pore (sample 13). 43. Close up of the central area internally, showing the narrow stauros located in a wider hyaline area, the central raphe endings with double helictoglossa, and the rounded to rectangular areolar openings internally (sample 13). 44. Close up of the apex, showing the bent distal raphe endings, cribrate areoale with up to six peripheral pores and up to two central pores (sample 13). 45. Close ups of both the valve exterior and interior (sample 11), showing the weakly expanded central raphe endings externally; the areolae near the raphe with usually four to five peripheral pores and one central pore; the central raphe endings with double helictoglossa and the rounded areolar openings internally. 46. Internal valve view, showing the narrow transverse rib of silica at the valve center (strauros) and the central raphe endings with double helictoglossa (sample 11). 47. Close up of the apex of the same valve internally, showing the rounded to square or rectangular areolar openings (sample 11). Scale bars = 5 μm (Fig. 46); 1 μm (Figs 42–45,47). in The genus Craspedostauros E.J.Cox (Bacillariophyta) on the coasts of Livingston Island, Maritime Antarctica