Biddulphia longicruris from Warri, Nigeria, in between two disc shaped diatoms. Deeply mounted (much deeper than the two others) with the processes and spine facing upwards towards the coverslip. Single central spine, which is unusual as they usually have 2. The circular feature just to the right of the middle of the diatom is I think the top of the spine as it was quite well defined in the original images, however the long thin body of the spine has been lost in stacking. Prepared by JA Long.
Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, slightly oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 102 images stacked in Zerene (Pmax).
Published in: Greville, R.K. (1859). Description of Diatomaceae observed in Californian guano. Quarterly Journal of Microscopical Science 7: 155-166. This name is currently regarded as a synonym of Hobaniella longicruris (Greville) P.A.Sims & D.M.Williams.