Unknown bivalves

[Emma]

Yes, Paul, the first one deffinetely has yellow colouring inside, so I agree with your identification: Tapes (venerupis) aurea. However, the brown one has no periostratum, it is actually that chocolate brown colour, and I have no idea what it could be. Do you have any other suggestions? I don't think it is Meretrix lusoria because, as I say, it hasn't got a periostratum. Thanks for your help.

Hello Pierre, I think it is too wide to be Anomalocardia. I think maybe the location is oriental (China, Japan), but I can't be sure. These shells belong to part collections I have been given over the years. Do you have any other suggestions? Thanks for your help.