Marine benthic diatoms of Guam: new records, Dictyoneis apapae sp. nov., and updates to the checklist Author Lobban, Christopher S. Division of Natural Sciences, University of Guam, Mangilao, GU 96923, USA clobban @ triton. uog. edu clobban@triton.uog.edu Author Witkowski, Andrzej University of Szczecin, Institute of Marine and Environmental Sciences Mickiewicza 16 a, PL 70 - 383 Szczecin, Poland text Micronesica 2023 2024-06-06 2023 2 1 75 journal article 299061 10.5281/zenodo.12118784 2b921c3c-8618-439e-96da-1de9c66a90f9 0026-279X 12118784 Amphora spectabilis Gregory Figs 3, 4 Ref. illus.: Levkov 2009 , p. 265, pl. 114, figs 1–5, pl. 252, figs 1–5 ( SEM ). Samples: GU55B-5 Dimensions: Length 30 µm, width 12 µm, stria density 8 in 10 µm (dorsal) and 13 in 10 µm (ventral) Diagnostics: More strongly and coarsely striated on the dorsal surface, dorsal striae often biseriate and bifurcating towards the sternum, ventral striae uniseriate. Comment: Our specimens (seen also in Yap and Palau ) are much shorter than the 68–129 µm given by Levkov (2009) . A Palauan specimen ( Fig. 4 ) seen in SEM shows that the striae are mostly biseriate, the bifurcations resulting from the two rows diverging; these images conform to the specimens shown by Levkov in SEM .