Apectodinium homomorphum subsp. quinquelatum

"subsp. quinquelatum" (Williams and Downie, 1966b, p.191-192, pl.18, fig.7) Lentin and Williams, 1977b, p.8.  Holotype: Williams and Downie, 1966b, pl.18, fig.7.  NOW Apectodinium quinquelatum.  Originally Wetzeliella homomorpha var. quinquelata, subsequently Wetzeliella homomorpha subsp. quinquelata, thirdly Apectodinium homomorphum subsp. quinquelatum, fourthly Wetzeliella quinquelata, fifthly (and now) Apectodinium quinquelatum.  Taxonomic senior synonym (at specific rank): Hystrichosphaeridium (now Apectodinium) geometricum, by implication in Harland (1979c, p.67), who considered the latter to be the junior name - however, Lentin and Williams (1989, p.18) retained Apectodinium quinquelatum.  Age: Early Eocene. Parent: Apectodinium homomorphum