There is no mark.  These would look good with the Heisey Greek Key pattern tho.  Let me know if you know who makes these vintage little bowls.  Also, what are they used for?  Thanks ahead of time.  Underplates are 4.25" .  More like a shallow bowl or dish  than a plate.  Cups are 1.75" highx2.25"wide.  These could be for anything you want.  Dipping sauces, open salt, fruit Nappy etc.