Scallops

Three kinds of scallops are typically sold in American fish stores. The largest are sea scallops, considerably smaller are bay scallops, and the smallest of all—they look like miniature marshmallows—are calico scallops, which are usually sold as bay scallops but are quite different.

You can buy sea scallops in their shell, which have a little fluted base and are easy to recognize because they are the symbol of Shell gas stations. Buying any shellfish in the shell is ideal because it ensures freshness. But most scallops are shucked on the boat, making it harder to gauge their freshness. The best test is to smell them. You should detect only the sea and never sulfur.