FIGURES 54–56 in The genus Afrocymbella (Bacillariophyceae) from lakes Malawi and Tanganyika, with description of new fossil and extant species

FIGURES 54–56. Afrocymbella nyassae sp. nov., SEM external valve views. 54. Half-valve showing uniseriate striae and single stigmoid positioned distally from the round, slightly asymmetric central area. 55. View of the whole valve showing raphe structure and striae continuing onto valve mantle. 56. Close view of distal raphe terminal fissure and APF of round poroids. Scale bars = 5 μm (Fig. 54), 2 μm (Fig. 55), 1 μm (Fig. 56).