Hystrichosphaeridium zoharyi Rossignol, 1962

Now Polysphaeridium. Originally Hystrichosphaeridium, subsequently Hemicystodinium, thirdly (and now) Polysphaeridium.
Possible tax. jr. synonym of Hystrichosphaeridium intermedium (O. Wetzel, 1933) Deflandre, 1937, according to Matsuoka, 1983. Lentin and Williams, 1989, retained Polysphaeridium zoharyi as a separate species.
Tax. sr. synonym of Polysphaeridium subtile Davey and Williams, 1966, according to Islam, 1983.
Lentin and Williams, 1989, retained Polysphaeridium subtile as a separate species after discussions with J.P. Bujak, who examined the holotype of Polysphaeridium subtile.
Tax. sr. synonym of Hemicystodinium? taugourdeaui (Varma and Dangwal, 1964) Sarjeant and Stover, 1978, according to Sarjeant and Stover, 1978, Stover and Evitt, 1978, and Lentin and Williams, 1981.
Wall and Dale, 1969, considered this species to represent the encysted stage of Pyrodinium bahamense Plate, 1906.
Matsuoka, 1989, considered this species to represent the encysted stage of Pyrodinium bahamense forma compressum Bohm, 1931.

Holotype: Rossignol, 1962, pl.2, fig.10
Age: Pleistocene