FIGURES 431–436 in The morphology and molecular phylogenetics of some marine diatom taxa within the Fragilariaceae, including twenty undescribed species and their relationship to Nanofrustulum, Opephora and Pseudostaurosira

FIGURES 431–436. Scanning electron micrographs of Serratifera rhombica (culture s0357 and wild material). Figs 431–433. External views, showing narrowly-lanceolate or linear sternum and complex volae, projecting from transapical (sometimes apical) side of areolae. Figs 434–435. Internal views, showing the absence of rimoportulae. Fig. 436. Girdle view, showing plain copulae and much wider valvocopulae. Figs 431–432, 434. Wild material from the coast of Nosy Be Island, Madagascar.