FIGURES 23–27 in Taxonomic revision and morphological cladistics analysis of the diatom genus Anorthoneis (Cocconeidaceae), with description of Anorthoneis arthus-bertrandii sp. nov.

FIGURES 23–27. Anorthoneis dulcis specimens from Hein (1991), original material #4138, Withlacoochee River, Fla, U.S.A, ANSP Material Collection, Philadelphia Academy of Natural Sciences, SEM images. (23) External view of sternum valve showing asymmetrical subtriangular central area; (24) Tilted external view (60°) of sternum valve showing the convex external mantle; (25) Internal view of sternum valve; (26) Detail of mantle showing the apically elongated areolae at the end of each stria; (27) Tilted internal view (60°) of sternum valve showing the slight thickening of sternum and central area. Scale bars: Figs 23–24, 29 = 5 μm; Fig. 25 = 2 μm; Fig. 26 = 1 μm.