FIGURES 16–22 in Two new Orthoseira species (Bacillariophyceae) from lava tubes on Île Amsterdam and Big Island (Hawai΄i)

FIGURES 16–22. Orthoseira verleyenii Van de Vijver sp. nov. Scanning electron micrographs. Fig. 16. External view of an entire valve showing two carinoportulae, the small hyaline central area and the rows of areolae and the (eroded) regularly placed linking spines. Fig. 17. External view of an entire valve showing two carinoportulae, a more irregular pattern of areolae and a larger hyaline central area and regularly placed linking spines. Fig. 18. Detail of the valve face/mantle junction. Fig. 19. External valve face view of an entire valve showing three carinoportulae. Figs 20–22. Detail of several arrangements of carinoportulae. Note the presence of weakly raised rims around the carinoportulae. Scale bar represents 10 µm in figs 16–19 and 1 µm in figs 20–22.