Hi,
It is Canadian Roden Bros, Toronto, Ontario.
Gothic R into a square STERLING and pseudo English lion passant hallmarks.
Company founded June 1, 1891 in Toronto by Thomas and Frank Roden. In the 1910s the firm became known as Roden Bros. Ltd. and were taken over by Henry Birks and Sons in 1953.
Regards
Hi - your piece is a bon-bon spoon rather than a sugar sifter (sugar would pour through those holes rather than sprinkle), the pattern is 'Louis XV', produced Canadian firms Birks and P.W. Ellis, as well as Roden Bros. (American maker Whiting Mfg. introduced 'Louis XV' in 1891, later also produced by Gorham).