FIGURES 66–78 in Orthoseira variabilis sp. nov., a new diatom from a snow patch in Potter Cove, King George Island, Antarctica

FIGURES 66–78. Orthoseira variabilis sp. nov. SEM. Specimens in internal valve view. Figs 66–72. Whole valve views. Note valves with shallow or inconspicuous caverns (arrows). Figs 73–78. Details of valve surface, showing areolar structure, carinoportulae, etched slits (Figs 73–74, arrows), and shallow caverns (Figs 76–78); note small unoccluded perforations among the areolae (arrowheads). Fig. 75 is a detail of Fig. 71, rotated. Fig. 76 is a detail of Fig. 72. Fig. 77 is a detail of Fig. 70. Fig. 78 is a detail of Fig. 66. Scale bar: 10 µm (Figs 66–72), 2 µm (Figs 73–78).