Confidence: I'm as sure as I can be.
Notes: I think I was wrong above. When familiar with a Queen Scallop, there are many more ribs than above. There are only 12 bold ribs above, not enough for Aequipecten opercularis. This shell is much more consistent with the King Scallop, Pecten maximus. Sorry for the misleading ID above. The ribs are far too big here and too few in number for a Queenie.