FIGURES 172–180 in The biogeographic distribution of Cavinula (Bacillariophyceae) in North America with the descriptions of two new species

FIGURES 172–180. SEM micrographs of Cavinula vincentii Antoniades & Hamilton. Figs 172, 173, 175–179. External view. Figs 174, 178, 180. Internal view. Fig. 175. External view showing the pore-like fissure (arrow). Fig. 178. Internal view showing the pore-like fissure (arrow). Figs 172–180. Ellesmere Island, Alert, White Pond, Nunavut, Canada (type material). Scale bars: 2 μm in Figs 175–179; 5 μm in Figs 172–174, 180.