Thanks for replying, George.Now I have found this from the same seller:
ORIGINAL HOLOPHANE BOX! Verlys Satin Frosted Flower Bowl Hexagon
FootedCombining what the seller wrote, and what I have found, Holophane
is Verlys, and your mark is Holophane (or...
search: "Verlys Frosted Glass Love Bird Vase With Holophane Makers Mark!
Fenton Sticker" on ebay. I did find that in France, Holophane made some
art glass using Verlys molds. Looking at the history of Holophane, there
is a mark that looks like yours....