The Cream of the Jest was published in 1917 in its own volume. It was reissued in 1922 with an introduction by Harold Ward. It was included in the Modern Library in 1927. It was always subtitled A Comedy of Evasions. The edition edited by Joseph Flora, and the Wildside, Kessinger and other generic reprints are of the stand-alone edition.
In 1930, in the collected Works of Cabell (the Storisende edition), Cream was combined in one volume with The Lineage of Lichfield and so they shared the subtitle Two Comedies of Evasion. This double edition is the one that that was reissued in the Ballantine Adult Fantasy series with an introduction by Lin Carter (and an isbn prefix beginning with 0345-).
Stand alone editions of Cream have now been separated from Cream+Lineage double editions (containing two distinct works), and should not be combined. Probably a few inadequately described copies are in the wrong group, but the double edition can be identified by "Lineage" or "Two Comedies" or "Lin Carter" or "Ballantine" or an isbn beginning with "0345".
Stand-alone editions can be identified by the Harold Ward intro, or the Modern Library imprint, or a publication date before 1930, or the lack of the above described double-edition markers.
The presence of illustrator Frank C. Pape, in the absence of other markers, is ambiguous: the early McBride and John Lane Pape-illustrated edtions were stand-aliones, but the Ballantine double-edition added the Pape illustrations to the Storisende text.