Hystrichosphaeridium duplum subsp. parvum

"subsp. parvum" (Rozen, 1965, p.303–304, pl.4, fig.6; text-fig.13) Lentin and Williams, 1989, p.181.  Holotype: Rozen, 1965, pl.4, fig.6; text-fig.13.  Name illegitimate: the species name is illegitimate.  NOW Hystrichosphaeridium recurvatum subsp. parvum.  Originally Hystrichosphaeridium recurvatum var. parvum, subsequently (and now) Hystrichosphaeridium recurvatum subsp. parvum, thirdly Hystrichosphaeridium palmatum subsp. parvum (combination illegitimate), fourthly (and now) Hystrichosphaeridium duplum subsp. parvum (combination illegitimate).  Age: late Eocene.

Parent: Hystrichosphaeridium duplum