FIGURES 24–30 in Entogoniopsis gen. nov. and Trilamina gen. nov. (Bacillariophyta): a survey of multipolar pseudocellate diatoms with internal costae, including comments on the genus Sheshukovia Gleser

FIGURES 24–30. Scanning electron micrographs of Entogoniopsis grunowii from Vema Cruise 18, Core 112 (Figs 24–25, 27) and Vema Cruise 17, Core 107 (Figs 26, 28–30), South Atlantic Ocean. Fig. 24: Oblique external view. Note the location of the hyaline marginal ridge below the highest level of the valve face (black arrow), and the central ring of rimoportulae (arrowhead). White arrow indicates the furrow above the hyaline margin of the mantle. Fig. 25: Oblique internal view, showing the location of the central ring of rimoportulae (arrowhead), bifurcations of costae on the mantle, and the inwardly expanded hyaline margin of the mantle. White arrow indicates the furrow above the hyaline margin of the mantle. Fig. 26: Detail of the specimen in Fig. 29, showing well-preserved volae. Fig. 27: Detail of the specimen in Fig. 24, showing fractured non-buttressed external tubes of the rimoportulae (arrow). Fig. 28: Detail of the specimen in Fig. 25, showing internal openings of the rimoportulae arranged in a regular ring. Fig. 29: Oblique internal view of a hypovalve with attached valvocopula (VC), and a detached band of the epicingulum showing a fimbriate edge (arrow). Fig. 30: Detail of the specimen in Fig. 29, showing clasping devices that attach the valvocopula to the internal costae (arrow).