Two examples of Triceratium fractum from Oamaru, New Zealand. No makers name, but based on style and handwriting, I think this was prepared by WA Firth. Olympus BHB microscope using 450nm LED light. 40x Leitz Pl Apo NA 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 69 images stacked in Zerene (Pmax).
Triceratium fractum W.C.Walker & H.H.Chase 1887. Published in: Chase, H.H. & Walker, W.C. (1887). Some new and rare diatoms. Series II-III. pp. 1–12, Photoplates 3-5. Flint, Michigan: Daily News Print. Page 4, Plate 3, Figure 8. This name is currently regarded as a synonym of Triceratium castellatum var. fractum (W.C.Walker & H.H.Chase) Grunow. Source of synonymy: Grunow, A. (1888). Referate. Grove, E. and Sturt, G. On a fossil marine diatomaceous deposit from Oamaru, Otago, New Zealand (Journal of the Quekett Microscopical Club. Ser. II Vol. III. No. 18 and No. 19.1887. Part III and appendix.). Botanisches Centralblatt 34(2/3): 34-41.