Hystrichosphaeridium meson

"meson" Eisenack, 1955, p.179.  Holotype: Eisenack, 1954a, pl.1, fig.3.  NOW Visbysphaera mesa (Appendix A).  Originally Hystrichosphaeridium intermedium (name illegitimate), subsequently Hystrichosphaeridium meson, thirdly Baltisphaeridium meson (Appendix A), fourthly (and now) Visbysphaera mesa (Appendix A), fifthly Multiplicisphaeridium meson (Appendix A).  Substitute name for Hystrichosphaeridium intermedium Eisenack, 1954a, p.208, pl.1, figs.3,9; text-figs.3–4 (an illegitimate name).  Taxonomic junior synonym: Baltisphaeridium (subsequently Multiplicisphaeridium) micropilare Cramer, 1970, an acritarch species, according to Ye Xiaorong (1984, p.42).  Age: Silurian (late Llandovery–late Ludlow).

Parent: Hystrichosphaeridium