This is a pair of Anchor Hocking Fire-King Currier & Ives pattern custard cups. Each holds 6 oz. Each is 3 3/4" wide. They are in excellent condition with no chips or cracks.
It is white milk glass with the blue Currier & Ives scene front and back. The glass is not marked, but it was produced by Anchor Hocking in the 1970s to go with the Royal China Currier & Ives pattern.
I have recently seen people calling this and other Anchor Hocking Currier & Ives pieces Marcrest, but that is wrong. Marcrest was a china company and Anchor Hocking made glass pieces with these same shapes to go with some Marcrest patterns. None of those patterns were Currier & Ives, and Marcrest did not produce glass, anyway.