From Williams et al., 2017:

[Pterocystidiopsis, Deflandre, 1937b, p. 90.
Acritarch genus.

Tax. jr. syn.: Caddasphaera, by implication in Courtinat in Courtinat and Gaillard (1980, p.80), who transferred the "type species" of Caddasphaera, Caddasphaera halosa, to Pterocystidiopsis — however, Lentin and Williams (1981, p.31,237) retained Caddasphaera.
This name was not validly published in Deflandre (1935, p.234) since no description was given.

Type species: Pterocystidiopsis stephaniana, Deflandre, 1937b (pl.17 (al. pl.14), figs.7–8)]