FIGURES 23–27 in Two new Orthoseira species (Bacillariophyceae) from lava tubes on Île Amsterdam and Big Island (Hawai΄i)

FIGURES 23–27. Orthoseira verleyenii Van de Vijver sp. nov. Scanning Electron Micrographs. Fig. 23. Internal view of an entire valve showing two carinoportulae, a large hyaline central area and areolae arranged in small striae near the valve face/mantle junction. Fig. 24. Internal view of a broken valve focusing on the valve face/mantle transition. Two carinoportulae are visible. Figs 25–27. Internal detail of several arrangements of carinoportulae. Note the presence of small slits between carinoportulae. Scale bar represents 10 µm in Figs 23–24 and 1 µm in Figs 25–27.