For a long time comedienne Gene Marsh has been known to have appeared in Charlie Chaplin's last Keystone film, His Prehistoric Past as one of the cave girl wives of Mack Swain's "King" character. This identification was included in Theodore Huff's 1951 Chaplin filmography, which was reprinted in his biography of the same year.
Since then there has been confusion between this actress and another who appeared in many Chaplin Keystones, due to the fact that she plays another (and a much more evident) of the King's wives in that film. Because she was so ubiquitous in Chaplin's 1914 films, it was assumed by some (including this author) that this actress was Marsh. After further research this has proven to be false. The actress in question has been provisionally identified as Peggy Page (possibly a stage name for Helen Carruthers).
The actual Gene Marsh was in only the one Chaplin film, His Prehistoric Past, before moving on to the Rolin Film Company, founded by Hal Roach and Dan Linthicum , to work with Harold Lloyd in his Lonesome Luke comedies. Here's her biography from Motion Picture Magazine's October 1916 Studio Directory:
Here she is with Chaplin in His Prehistoric Past:
And here, seated next to Chaplin is the other actress who was identified as Marsh, Peggy Page. Gene Marsh is in the group above, third from the right.
Now here is Marsh, along with Harold Lloyd, Bebe Daniels and Snub Pollard in two ads for the Rolin comedies:
Finally, here's a cast photo from Rolin including Lloyd, Pollard, Hal Roach and the manager of Rolin, Dwight Whiting. Gene Marsh is second row extreme right.:
It's clear from comparing these photographs that the "Water Maiden" (as Huff called her) from His Prehistoric Past is the same actress in the Rolin Phunfilms, Gene Marsh.