Hystrichosphaeridium biformoides

"biformoides" Eisenack, 1954b, p.68, pl.11, figs.16–20.  Holotype: Eisenack, 1954b, pl.11, fig.18.  NOW Achilleodinium.  Originally Hystrichosphaeridium, subsequently Baltisphaeridium (Appendix A), thirdly Hystrichokolpoma, fourthly (and now) Achilleodinium, fifthly Florentinia.  Age: late Eocene–early Oligocene.

Parent: Hystrichosphaeridium