dc:description"FIGURES 2–16. Cleaned frustules of Microcostatus salinus, showing the morphological variation among individual cells (scale bar = 5 μm). Note the longitudinal line near the valve margin (Fig. 2, arrow), which in fact is the gap between the conopeum and the elevated part along the valve margin. In addition, in some individuals the conopeum is not well developed and appears the longitudinal elevated part along axial area under light microscope (Fig. 5, arrow). The central raphe endings are inconspicuous, usually appearing as depression points (Figs 3, 14, arrows).";
dc:description"FIGURES 17–19. Valve views of Microcostatus salinus with SEM and TEM (scale bars = 2 μm). Note the different distances between the two central raphe endings on the external and internal valve surfaces. The striae are present near the two valve apexes. The nonperforated conopea cover about 1/2 of valve width (Figs 17, 19, arrows).";
dc:description"FIGURES 20–28. SEM micrographs of Microcostatus salinus. 20. Widely spaced central raphe endings in external valve view (arrows). 21. Relatively closed central raphe endings in internal valve view (arrowheads). 22.TEM micrograph showing the central raphe endings in external (arrow) and internal valve view (arrowhead). 23. External view of cell apex, showing the external microcostae (arrowheads). Note the external interrupted elongate areolae (arrow and double arrows). 24. Internal cell apex, showing the raphe branch ending in a small helictoglossa (arrow). 25. TEM micrograph of valve end, showing the striae which are composed of two elongate areolae. 26. External view of a cell apex showing the two cingula, including one valvocopula (arrowhead), and the nonperforated conopeum extending from raphe sternum (arrow). 27. Internal view of valve apex, showing the striae composed of two elongate areolae, the proximal one (arrow) occluded with a hymen internally, whereas the distal one (double arrows) occluded with a hymen externally.28. TEM micrograph showing the areolae occluded by a perforated hymen. All scale bars = 1 μm, except Fig. 22 (0.5 μm) and Fig. 28 (0.2 μm).";
