From Williams et al., 2017:

[Votadinium, Reid, 1977, p. 444

Originally (and now) Votadinium, subsequently Protoperidinium subgenus Protoperidinium section Votadinium (combination not validly published).
Contrary to the opinion of Lentin and Williams (1993, p.666), we consider this name not to be illegitimate.

Type species: Votadinium calvum, Reid, 1977 (pl.2, fig.21)]

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Original description: [Reid, 1977]:

Diagnosis:
Peridinoid shaped cysts with a rounded apex or elongate apical horn and with two antapical, rounded horns or lobes separated by an antapical depression which may be deep or shallow.
Test compressed dorsoventrally, no evidence for a girdle.
Archeopyle intercalary.