FIGURES 47−57. H in Seven new species expand the morphological spectrum of Haslea. A comparison with Gyrosigma and Pleurosigma (Bacillariophyta)

FIGURES 47−57. H. clevei sp. nov., SEM. figs 47–53. Type material, Finnmark, Norway. figs 54–57. Material from Florida, USA. SEM. Fig. 47. General aspect, exterior, bar = 20 μm. Inset: detail, magnified 4x, showing offset striae. Fig. 48. General aspect, interior, bar = 20 μm. Fig. 49. Centre, interior, bar = 2 μm. Note vestigial central bar. Fig. 50. Centre, exterior, bar = 2 μm. Inset (2x enlargement): central raphe endings in "pits", almost fused. Fig. 51. Apex, exterior, bar = 2 μm. Fig. 52. Apex, interior, bar = 2 μm. Note prominent helictoglossa. Fig. 53. Interior view of valve where basal and tegumental layer have separated, bar = 2 μm. Inset (2x enlargement): saepes with large perforations (arrow) located underneath the transverse basal layer bars. Figs 54, 55. Apex, exterior, 2 different specimens, bars = 1 μm. Valve morphogenesis not yet finished, longitudinal fissures still to be filled in. Arrows mark perforations in saepes. Fig. 56. Centre, exterior of developing valve, longitudinal fissures still to be filled in. Horizontal arrow marks raphe endings in "pits", oblique arrows mark perforations in saepes. Bar = 3 μm. Fig. 57. Centre, interior. Vestigial central bar, compare with Fig. 49 for variability. Bar = 2 μm.