Pseudictyota bicornis (Cleve) P.A.Sims & D.M.Williams

Lobban, Christopher S. & Witkowski, Andrzej, 2023, Marine benthic diatoms of Guam: new records, Dictyoneis apapae sp. nov., and updates to the checklist, Micronesica 2023 (2), pp. 1-75 : 15

Pseudictyota bicornis (Cleve) P.A.Sims & D.M.Williams Figs 91–93

Ref. illus.: Cleve 1878, fig. 30; Ashworth et al. 2013, fig 7b; Sims et al. 2018, figs 133–138

Sample: GU52U-1

Dimensions: 51 µm long (on the axis with the ocelli), 42 µm wide

Diagnostics: Quadrate, false pseudoloculate valve, having two elevations with ocelli and two unelevated points with rimoportulae.

Comments: Differing from Pseudictyota dubia (Brightwell) P.A.Sims & D.M.Williams ( Navarro & Lobban 2009, figs 21–24), which has six angles, three with ocelli and three with rimoportulae; and from P. reticulata (Roper) P.A.Sims & D.M.Williams ( Lobban et al. 2012, pl. 3, figs 3, 4, as Triceratium dictyotum P.A.Sims & R.Ross ), which is broadly lanceolate with two angles each with both an ocellus and a rimoportula.

Figures

Figures 91–97. Pseudictyota and Serratifera, SEM except Fig. 91. Figs 91–93. Pseudictyota bicorne. Fig. 91. Frustule in girdle view, stacked focal planes. Figs 92, 93. Valve view in SEM and detail of pseudoloculi. Figs. 94, 95. Serratifera andersonii frustules in valve and girdle view. Figs. 96, 97. Serratifera rhombica frustules in valve and girdle view. Scale bars: Fig. 91 = 10 µm, Fig. 92 = 15 µm, Fig. 93 = 5 µm, Figs 94–97 = 2 µm.