From Williams et al., 2017:

[Epicephalopyxis, Deflandre, 1937b, p.92.
Acritarch genus.

This name was not validly published in Deflandre (1935), since no type was designated, this being a requirement of the I.C.Z.N. at that time.

Type species: Epicephalopyxis adhaerens, Deflandre, 1937b (pl.18, fig.6), designated by Lentin and Williams (1989, p.130).]