Palaeoperidinium "nuciforme" Deflandre, 1939a, p.180, pl.8, figs.4–6. Holotype: Deflandre, 1939a, pl.8, fig.6; Jan du Chêne et al., 1986a, pl.11, figs.1–3. Name not validly published: generic name not validly published until 1967. NOW Cribroperidinium. Originally Palaeoperidinium (name not validly published), subsequently Gonyaulax (Appendix B), thirdly Gonyaulacysta, fourthly Apteodinium, fifthly Millioudodinium, sixthly (and now) Cribroperidinium. Taxonomic junior synonym: Palaeoperidinium nuciformoides, according to Sarjeant (1968, p.227). Age: Oxfordian.