Bittersweet Clam: Family Glycymerididae
The Bittersweet clam shells are common on my beach and Florida beaches. They are bi-valves somewhat related to Ark shells but are round. The two predominat types are the Giant Atlantic Bittersweet and the Spectral Bittersweet. Two other types in my collection, the Combs Bittersweet and the Spiny Papercockle/Square Papercockle shells are sometimes found on S. Hutchinson Island beaches. The papercockle shells resemble the purple semele shells except they thin ribs extending from the umbo. The Giant Bittersweet may reach 5" in size and is round with a beaked umbo. It's a white shell that features intricate brown patterns circling around the umbo and extending toward the bottom. Smaller versions of the shell (1/2' or smaller) have more intense patterns. The Spectral Bittersweet clam shells (around 1/2 to 1") are attractive for their patterns of brown and white. Spectral Bittersweets are round shells and range from dark brown to pure white.