Membranilarnax pterococcoides O. Wetzel, 1933; Emendation: Sarjeant, 1985b, p.154-155, as Eatonicysta pterococcoides.

NOW Membranilarnacia. Originally Membranilarnax, subsequently (and now) Membranilarnacia, thirdly Membranilarnacia?, fourthly Eatonicysta.
Holotype: O. Wetzel, 1933, pl.6, fig.4;Sarjeant, 1985, pl.4, figs.3,6 [non 1,2]
Age: Senonian