Navicula lewisiana on a Diatom test object slide. Also known as Frikea lewisiana. Prepared by Samuel Meakin. Dated 1945. Two large disc diatoms at either end of the arrangement. Diatoms from left to right; 1. Triceratium favus. 2. Pinnularia nobilis. 3. Cymbella gastroides. 4. Navicula maculata. 5. Navicula lyra coarse. 6. Navicula lyra fine. 7. Stauroneis phoenicenteron. 8. Pleurosigma balticum. 9. Pleurosigma attenuatum. 10. Pleurosigma angulatum. 11. Navicula smithii. 12. Cymatopleura solea. 13. Navicula lewisiana (also known as Frikea lewisiana). 14. Brebissonia boekii. 15. Amphipleura lindheimeri. 16. Navicula rhomboides (Cherryfield). 17. Navicula rhomboides fine 18. Nitzschia singalensis. Olympus BHB microscope using 405nm light from a 50x Zeiss HBO mercury xenon lamp. 60x Olympus Splan Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, brightfield lighting. 3.3x Olympus NFK photoeyepiece. Monochrome converted Nikon d800 camera. 8 images stacked in Zerene (Pmax).