FIGURES 41–46 in Three new species of Ulnaria (Bacillariophyta) from the Wuling Mountains Area, China

FIGURES 41–46. Ulnaria ulnabiseriata sp. nov., external view, SEM. 41. One whole valve. 42–43. Details of the previous two poles, note the alternate striae. 44–46. Details of the middle parts of the previous whole valve, note the opposite striae and biseriate striae becoming uniseriate striae at the end of each stria. Scale bar =10 μm (Fig. 41), 5μm (Figs 42–46).