From Fensome et al., 2019:
Hystrichosphaeridium raritanianum Kimyai, 1966, p.471, pl.2, fig.19. Holotype: Kimyai, 1966, pl.2, fig.19. Originally
Hystrichosphaeridium, subsequently (and now) Hystrichosphaeridium?. Questionable assignment: Stover and Evitt
(1978, p.56) as a problematic species. Age: Cenomanian.

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Original diagnosis: Kimyai, 1966, p.471
Body almost circular in equatorial contour, laevigate; appendages 4-6 µm long, 3-6 µm wide, variable in shape; tips of appendages irregularly bifurcate; number of appendages 8-12.
Dimensions: Equatorial diameter 39-46 µm. Holotype: Equatorial diameter 42 µm.

Affinities:
Kimyai, 1966, p.471: This form differs from Hystrichosphaeridium tubiferum by its short, wide appendages and larger central body.