Pogoneis bahrainii F.E. Round & P.W. Basson Figs 107–113

ORDER and Family incertae sedis

Ref. illus.: Round & Basson 1997, figs 1–3, 13–25

Samples: GU44I-4

Dimensions: 15–17 µm long, 2.3–2.7 µm wide; striae 45 in 10 µm (both valves).

Diagnostics: The monoraphid frustules are very distinctively shaped like a canoe in girdle view because of thickenings on raphe valve (RV) apices and the curvature of the sternum valve (SV). Striae are parallel and comprise slits which are apically elongated on both valves, except diagonal near RV apices.

Comments: Dimensions and stria densities agree with Round & Basson’s material from Bahrain. A slide from this sample with the holotype of Cyclophora minor (accession #627405, slide 223019) at California Academy of Sciences also has a marked specimen of P. bahrainii . The taxonomic position of this genus was not specified by Round & Basson (1997); as a monoraphid diatom it could have been placed in Achnanthales, but since Cox (2006) removed Achnanthes sensu stricto to Mastogloiales, there is no single order to which all monoraphid taxa belong.