Xanthidium crassipes Reade, 1839, pl.9, figs.2–5. Emendation: Lejeune-Carpentier and Sarjeant, 1981, p.10, as Hystrichokolpoma? crassipes.

Now Hystrichokolpoma. Originally Xanthidium, subsequently Hystrichosphaeridium, thirdly Litosphaeridium?, fourthly (and now) Hystrichokolpoma.
Tax. sr. synonym of Pervosphaeridium truncigerum (Deflandre, 1937) Yun, 1981, by implication, according to Yun, 1981, who considered Pervosphaeridium truncigerum to be the sr. synonym; however, Lentin and Williams, 1985 retained Peruosphaeridium truncigerum as a separate species.

Holotype: Reade, 1839, pl.9, fig.2; lost, according to LejeuneCarpentier and Sarjeant, 1981
Neotype: Lejeune-Carpentier, 1941, fig.9 and Lejeune-Carpentier and Sarjeant, 1981, pl.3, fig.3; text-fig.6; designated by Lejeune-Carpentier and Sarjeant, 1981
Age: Late Cretaceous