Hystrichosphaeridium brevispinosum var. nanum Deflandre, 1945

NOW Polygonium nanus. Originally Hystrichosphaeridium brevispinosum var. nanus, subsequently Baltisphaeridium brevispinosum var. nanus (combination not validly published), thirdly Baltisphaeridium nanus, fourthly Micrhystridium nanus, fifthly (and now) Polygonium nanus, sixthly Solisphaeridium nanus.
Taxonomic junior synonym: Baltisphaeridium brevispinosum var. wenlockense (subsequently Salopidium wenlockense) Downie, 1959, an acritarch taxon, according to Lister (1970, p.54).
This name was not validly published in Deflandre (1942, fig.1 - p.476), who did not give a description.

Holotype: Deflandre, 1945, pl.1, figs.5-6
Age: Silurian