An arrangement of Monopsia sp. from Singiliewsky, USSR. Two Monopsia corrugata, and two Monopsia concentrica, one partial and one intact of each. Mounted in Styrax/Aroclor, and dated Xmas 1972. Prepared by Richard Gosden. Olympus BHB microscope using 450nm LED light. As well as imaging the arrangement with a 20x Nikon Plan Apo NA 0.65 objective and oblique lighting. Frustratingly, I couldn’t get close enough with the 63x Leitz Pl Apo objective, so I had to use the 40x Leitz Pl Apo NA 1.00 objective, oil immersion (which limited the achievable resolution). Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Image stacks prepared in Zerene (Pmax).
Monopsia corrugata Barker & Meakin 1944. Published in: Barker, J.W. & Meakin, S.H. (1944). New genera and species of diatoms from Russia. Journal of the Quekett Microscopical Club, Series 4 1(6): 251-255, pls 38,39. Page 254, Plate 39, Figure 10.
Monopsia concentrica Barker & Meakin 1943. Published in: Barker, J.W. & Meakin, S.H. (1944). New genera and species of diatoms from Russia. Journal of the Quekett Microscopical Club. Series 4 1(6): 251-255, pls 38,39. Page 254, Plate 39, Figure 9.
The slide was quite low contrast, and I suspect the diatoms were mounted relatively deeply (there are three spacers for the coverslip, visible from the rear of the slide).