Protoperidinium tholus (Bradford, 1975, p.3072,3074, figs.17–22) Bradford and Wall, 1984, p.49.

Combination not validly published: basionym not fully referenced. NOW Selenopemphix. Originally Omanodinium, subsequently Protoperidinium subgenus Protoperidinium section Selenopemphix (combination not validly published), thirdly Selenopemphix (combination not validly published), fourthly (and now) Selenopemphix. N.I.A.

Holotype: Bradford, 1975, fig.17.
Age: Holocene.