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Keywords from Image Description:
Radiolaria Challenger Plate . follows Plate Phacodiscida Diam Fig Sethodiscus lenticula sp Fig Sethodiscus lenticula sp Vertical section Fig Sethodiscus macrococcus sp Young shell not yet closed seen from the margin Fig Periphna cincta sp Fig Triactiscus tricuspis sp Marginal view Fig Triactiscus tripyramis sp