Combine all ingredients including diced clams. If the mixture is too dry, add a tablespoon or two of fresh clam juice.
Place the clam mixture in a single layer on the half shells and place on a cookie sheet.
Bake at 350 degrees for 15-20 minutes, then broil for a few minutes until crumb mixure browns lightly and crisps. Watch carefully so as not to cook clams too much because they can get tough. Clams should be soft and juicy. Serve immediately with lemon wedges.