A strew of diatoms from the surface of intertidal sand, Seahouses, Northumberland (UK). Mainly Donkinia recta and Toxonidea gregoriana (spelt gregoryana on the slide). Mounted in Naphrax and dated 22nd August 1981. Prepared by Ray Parkinson. Olympus BHB microscope using 450nm LED light. 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 Nikon d850 camera. Image stacks prepared in Zerene (Pmax).
Toxonidea gregoriana. 16 images stacked. Spelt gregoryana on the slide. Toxonidea gregoriana Donkin 1858. Published in: Donkin, A.S. (1858). On the marine Diatomaceae of Northumberland with a description of eighteen new Species. Transactions of the Microscopical Society of London, Series 2 6: 12-34, pl. III. Page 19, Plate 3, Figure 1.
Donkinia recta. 18 images stacked. Donkinia recta (Donkin) Carruthers 1864. Published in: Carruthers, W. (1864). The Diatomaceae. In: Handbook of British water-weeds or algae. (Gray, J.E. Eds), pp. 75-116. London: R. Hardwicke, Piccadilly. Page 113. Accepted name: Pleurosigma rectum Donkin, 1858.