Bit of a mystery this one. Slide labelled as Biddulphia ‘calapora’ (fragment) from Forrester’s Hill, Oamaru, New Zealand. Dated 18th September 1969. Metal spacers for the coverslip. Prepared by Richard Gosden. Olympus BHB microscope using 450nm LED light. 20x Nikon Plan Apo NA 0.65 objective. Olympus Aplanat Achromat condenser, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 61 images stacked in Zerene (Pmax). Couldn’t get close enough with the 40x or 63x Leitz Pl Apo objectives.
Not sure what to make of this slide. ‘Calapora’ means ‘the horse’ in Romanian (thanks Google Translate), but I can find no connection to diatoms. How is that relevant? Any thoughts as to what this is a fragment of, please drop me an email.