An arrangement of three Doryphora boeckii from Quinnipiac (spelt Quininpiac on the slide) River, Connecticut. No name, but I think this is by JA Long. Olympus BHB microscope using 450nm LED light. I selected one of them (the right hand side one in the arrangement) for further imaging. 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. 25 images stacked in Zerene (Pmax).
Doryphora boeckii (Ehrenberg) W.Smith 1853. Published in: Smith, W. (1853). A synopsis of the British Diatomaceae; with remarks on their structure, function and distribution; and instructions for collecting and preserving specimens. The plates by Tuffen West. In two volumes. Vol. I. pp. [i]-xxxiii, 1-89, pls I-XXXI. London: John van Voorst, Paternoster Row. Page 77, Plate 24, Figure 223. This name is currently regarded as a synonym of Brebissonia lanceolata (C.Agardh) R.K.Mahoney & Reimer 1986. Published in: Mahoney, R.K. & Reimer, C.W. (1986). Studies on the genus Brebissonia (Bacillariophyceae). I. Introduction and observations on B. lanceolata comb. nov. Proceedings of the International Diatom Symposium 8: 183-190. Page 184, Figures 1-18.
Basionym: Cocconema boeckii Ehrenberg 1834.
I can just about make out the striae details and some of the structure in the apices on this one.