An arrangement of three Amphitetras ornata (written as ornatus on the slide) from Java. No makers name, but I think it could be by Watson and Sons Ltd (although the metal disc in the middle reminds me of other makers such as J Tempère, so now I think about it I am less sure). Olympus BHB microscope using 450nm LED light. As well as arrangement I imaged one using the 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted d850 camera. 48 images stacked in Zerene (Pmax). This was the one on the left in the arrangement and was ‘rim down’. The other two were ‘rim up’, i.e. underside views.
Amphitetras ornata Shadbolt 1854. Published in: Shadbolt, G. (1854). A short description of some new forms of Diatomaceae from Port Natal. Transactions of the Microscopical Society of London ser. 2 2: 13-18. Page 16, Plate I, Figure 10. This name is currently regarded as a synonym of Biddulphia ornata (Shadbolt) Castracane 1886. Published in: Castracane, [C.A.] F. (1886). Report on the Diatomaceae collected by H.M.S. Challenger during the years 1873-76. In: Report on the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873-76. Botany. Vol. II. (Murray, J. Eds), pp. [1]-178. Page 105.