Hystrichosphaeridium calvum

?calvum Tasch in Tasch et al., 1964, p.193, pl.1, fig.21.  Holotype: Tasch et al., 1964, pl.1, fig.21; Fauconnier and Masure, 2004, pl.43, figs.9–10.  Originally Hystrichosphaeridium, subsequently (and now) Hystrichosphaeridium?.  Questionable assignment: Stover and Evitt (1978, p.56) as a problematic species.  Age: Albian.

Parent: Hystrichosphaeridium