From Fensome et al., 2019:
Coronifera oceanica ssp. magna (Wetzel, 1955, p.35,38, figs.9–10,14) Sarjeant, 1984c, p.138–139. Emendation: Sarjeant, 1984c, p.138–139, as Coronifera oceanica subsp. magna. Holotype: Wetzel, 1955, fig.9; Sarjeant, 1984c,
pl.5, figs.4–5; text-fig.11 (two illustrations); Fensome et al., 1991, figs.1–3 — p.663; fig.1 — p.697.
Originally Hystrichosphaeridium pseudhystrichodinium subsp. magnum, subsequently Baltisphaeridium
pseudhystrichodinium subsp. magnum (Appendix A), thirdly (and now) Coronifera oceanica subsp. magna,
fourthly Coronifera pedata subsp. magna. Lentin and Williams (1989, p.77) retained this taxon as a
subspecies of Coronifera oceanica. Age: Paleocene.

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Original description: [Wetzel, 1955] (translated from German):

Hystrichosphaeridium pseudhystrichodinium DEFL. 1937 magnum n. subsp.
Figs. 9, 10 and 14

Holotype: Fig. 9. Original contained in preparation cat. 1, kept in the collection of the Kiel Geological Institute.

Within the plankton association from Katharinenhof, a form occurs particularly frequently that is said to be related to a Senon species of DEFLAN-DRE as a subspecies, but which appears separate due to its considerably larger dimensions. It is even The largest of all Hystrichosphaeridia observed in the Katharinenhof material. While Delfandre's type has a maximum diameter of 90 μ, specimens from our material measured 168 μ, with the capsule alone accounting for 98 μ. Otherwise, the similarity to Deflandre's species type is very high.
Number of specimens examined: 14.