This is one of many reproduction marks found on fake Roseville Pottery imports. Notice the shape of the "R" in Roseville and the way the letters are straight rather than slanted slightly to the right. While the absence of U.S.A. is a clue to reproduction marks in some cases, it's not always an indicator. You will see a photo of a genuine Roseville U.S.A. mark in the next photo.
Note: Check out the Roseville resources link shown at right to view and compare more Roseville marks.