Triceratium excentricum (also seen spelt eccentricum) from Allan’s Farm, Oamaru, New Zealand. Single example on the slide. Incomplete. Prepared by Richard Gosden. Mounted in Sty.Arac. (presumably Styrax, Araclor) and dated March 1966. Olympus BHB microscope using 450nm LED light. 50x Leitz Fluoreszenz 1.0 objective, water immersion. Olympus Aplanat Achromat condenser, oil immersion, slightly oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 48 images stacked in Zerene (Pmax). A quick note about the objective. This one has a very long working distance (0.68mm) which was necessary as my usual Pl Apo ones couldn’t even get close to it. The final image is lower contrast and lacks the punch of the ones from the Pl Apo objectives, but if the alternative is ‘no image’, then I consider this a success.
Original description along with a beautiful drawing and where is it spelt Triceratium eccentricum (screen grabs shown above): Grove, E. & Sturt, G. (1887). On a fossil marine diatomaceous deposit from Oamaru, Otago, New Zealand. Appendix. Journal of the Quekett Microscopical Club, Series 2, 3(19): 131-148, pls 10-14. page(s): p. 137; pl. XIV, fig. 61 (p. 148).