An intriguing looking little diatom. Triceratium petitianum from Celebes (the former Dutch and Western name for the Indonesian island of Sulawesi). Single example on the slide, broken, but with the fragment so maybe that occurred during mounting (he must have been gutted if that was the case). Sty.Ar (Styrax Aroclor) mountant and dated October 1970. Leuduger-Fortm. Plate V/12. Diats. mar. cote occid t d’Afrique (more on this in a minute). Prepared by ECP Bone. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, slightly oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 37 images stacked in Zerene (Pmax). I’ve moved the fragments closer together (and rotated the smaller one) to remove some empty space in the image.
Triceratium petitianum Leuduger-Fortmorel, 1898. Original description: Leuduger-Fortmorel, G. (1898). Diatomées marines de la côte occidentale d’Afrique. Mémoires de la Société d’Emulation des Côtes-du-Nord. St. Brieuc. 1-41, pl. 1-8. Page 28, Plate 5, Figure 12. This is summarized on the label of the slide.
Synonymised names: Biddulphia petitiana (Leuduger-Fortmorel) Mann, 1925. Hydrosera petitiana (Leuduger-Fortmorel) F.W. Mills, 1934. Terpsinoë petitiana (Leuduger-Fortmorel) Hendey, 1971.