Pleurosigma angulatum (and others), fused piperine, Samuel Henry Meakin

Pleurosigma angulatum (and others), fused piperine, 10x Nikon Plan Apo NA 0.45 objective, brightfield

Pleurosigma angulatum (and others), fused piperine, 10x Nikon Plan Apo NA 0.45 objective, cross polarized

Pleurosigma angulatum, fused piperine mount

A strew slide of Pleurosigma angulatum (and others). Mounted in fused piperine (refractive index about 1.68) and dated July 1934. Prepared by Samuel Henry Meakin. Some crystallization of the piperine in the mount as shown in the cross polarized image. Olympus BHB microscope using 450nm LED light. I chose an example of Pleurosigma angulatum for imaging at higher resolution. 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. 24 images stacked in Zerene (Pmax).

Pleurosigma angulatum (J.T.Quekett) W.Smith 1852. Published in: Smith, W. (1852). Notes on the Diatomaceae with descriptions of British species included in the genus Pleurosigma. Annals and Magazine of Natural History, Series 2 9: 1-12, 2 pls. Page 7, Plate 1, Fig. 7, 8 [as var. beta], 9 [as var. gamma].