Cerataulus subangulatus (also referred to as Ceratangula subangulata), from Williams Boulder, Oamaru. Single example on the slide. Prepared by Emiliano Bellotti and mounted in Naphrax, 2024. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, brightfield, reduced condenser aperture. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 49 images stacked in Zerene (Pmax).