Multiplicisphaeridium piriferum (Eisenack, 1954) Eisenack et al., 1973

Now Visbysphaera (an acritarch genus). Originally Hystrichosphaeridium, subsequently Baltisphaeridium (an acritarch genus) thirdly Multiplicisphaeridium, fourthly (and now) Visbysphaera (an acritarch genus).
Tax. sr. synonym of the acritarch species Baltisphaeridium hermosum Cramer and Diez, 1968 (an invalid name), according to Cramer, 1970.
Holotype: Eisenack, 1954, pl.1, figs.1a-b
Age: Silurian (Late Llandovery)