FIGURES 48–52 in Analysis of the type material of Navicula brachysira Brébisson with the description of Brachysira sandrae, a new raphid diatom (Bacillariophyceae) from Iles Kerguelen (TAAF, sub-Antarctica, southern Indian Ocean)

FIGURES 48–52. Navicula brachysira. All pictures taken from the type population (Falaise). Fig. 48. External view of an entire valve showing the most typical features such as the marginal ridge, the striae always composed of (2)3 areolae, the simple raphe endings and the mantle striae. Fig. 49. Detail view of the central area. Not the presence of the papillae, the regular length of the areolae and the simple proximal raphe endings. Fig. 50. External detail of a valve apex with the typical axial ridge terminating before the marginal ridge, the simple, almost straight distal raphe endings, the T-shaped raphe groove near the apex and the diminishing number of areolae per stria. Fig. 51. Internal view of an entire valve. Fig. 52. Internal detail of the central area with the typical weakly bent proximal raphe endings and the porous hymenate internal coverings of the striae. Scale bar represents 10 µm, except for Figs 49, 50 & 52 where scale bar = 5 µm.