Notes on the diatom collection of the Natural History Museum, London (BM) VII: An account of some original specimens of Pyrgodiscus (Bacillariophyta) with notes on Stephanogonia (Bacillariophyta) Author Williams, David M. 0000-0002-0584-307X d. m. williams @ nhm. ac. uk; https: // orcid. org / 0000 - 0002 - 0584 - 307 X d.m.williams@nhm.ac.uk Author Sims, Pat A. 0000-0002-0214-8303 p. sims @ nhm. ac. uk; https: // orcid. org / 0000 - 0002 - 0214 - 8303 p.sims@nhm.ac.uk text Phytotaxa 2023 2023-03-28 589 3 213 229 http://dx.doi.org/10.11646/phytotaxa.589.3.1 journal article 10.11646/phytotaxa.589.3.1 1179-3163 7776942 Pyrgodiscus antiquus A.Forti & P.Schulz 1933: 244 , pl. 3, fig. 9, 10 =? TYPE :— GERMANY , “hannoverschen Gault” ( Forti & Schulz 1933, ‘“ Gault ” Formation ( Albian ) near Hannover (northwest Germany )’, Gersonde & Harwood 1990: 367 ) . Gersonde & Harwood commented on the locality, writing: “Unfortunately, Forti and Schulz 1933 [1932] did not indicate a type locality. According to Benda (1982), the deposit can no longer be located nor any original raw or type material” ( Gersonde & Harwood 1990: 367 ; see also Georgi 1976 ).