FIGURES 53–58 in Two new species of Nitzschia (Bacillariaceae, Bacillariophyta) from tropical reservoirs of southeastern Brazil

FIGURES 53–58. Type material of N. pusilluhasta sp. nov., SEM. 53, 54. Valve face in external view. 55. Valve edge showing raphe, first row of areolae, mantle, and pores in the valvocopula. 56. Central portion of valve face, areolae, and raphe. 57. Girdle and valve face views, near the apex showing areolae on valve and mantle, and poroids on the copulae. 58. Apex of the valve showing areolae on the valve face and mantle, raphe, keel and valvocopula poroids. Scale bars: Figs 53, 54 = 5 μm; Fig 55 = 0.5 μm; Figs 56–58 = 1 μm.