Keith — Yes, to confirm Christine's opinion. That eclectic rib pattern was a Walsh standard, found in mother of pearl as here and in other finishes. Probably Edwardian — we just don't know when they stopped making mother of pearl, although it was certainly not in regular production by the mid-20s.
... which brings up the question of whether you can say a glassworks ever stopped making anything. I suspect most old patterns and ranges could be made to order a very long time after regular production had ceased.