FIGURES 22–27. SEM micrographs of Eunotia petasum sp. nov. from the Giraffe Pipe fossil locality. 22. Dorsal view of a frustule showing the continuation of the striae from the valve face onto the mantle. 23. Ventral view of a valve depicting the raphe and reduced striae, often consisting of only 1–2 pores. 24. Interior view of a valve showing the continuation of the striae from the dorsal mantle onto the valve face. Striae on the ventral mantle are often reduced to random pores. 25. Exterior view of a valve depicting the narrow and protracted end and the distal raphe fissure. 26, 27. Internal views showing the striae, the open nature of the pores, the protracted apex, and the small rounded helictoglossa. Scale bars = 5 µm (Figs 22–26), 10 µm (Fig. 27).

Published as part of Siver, Peter A., Oddsund, Erik & Lott, Anne M., 2022, Descriptions of three new diatom species in the genus Eunotia (Eunotiaceae, Bacillariophyta) from the Eocene Arctic, pp. 21-35 in Phytotaxa 567 (1) on page 27, DOI: 10.11646/phytotaxa.567.1.2, http://zenodo.org/record/7137936