FIGURES 11–16 in Gyrosigma dongtingense sp. nov. (Bacillariophyta) from Dongting Lake, China

FIGURES 11–16. Gyrosigma dongtingense, sp. nov., SEM. 11, 13. Two valve types, either S-shaped or Ƨ-shaped, in external view. 12, 14. Middle part details from Fig. 11 and Fig. 13, respectively, note that both external proximal raphe fissures are deflected towards the convex side of each half-valve. 15, 16. Two valve types, either S-shaped or Ƨ-shaped, in internal view. Note the axial costa (four wavy arrows) along the raphe sternum. Scale bar = 10 μm (Figs 11–16).