The following is the text from a post by Tom Felt:
"Your comport looks like its base is the dolphin made by Portieux-Vallerysthal. Portieux-Vallerysthal is actually a pair of French companies, who probably first made this design in the nineteenth century. One of the factories is still operating today and has continued making the candlestick in recent years, frequently seen today since they are sold by A.A. Importing. (New dolphins are pretty easy to spot, because their quality doesn't compare with the older ones.) I've seen this dolphin used as a base for other comports and even fish globes, but never with a top like the one seen on yours. I'm guessing that your might date back to the 1930s (though that's strictly an "uneducated" guess, since French glass is not really my forte.)"