False Angel Wing
Petricola pholadiformis Lamarck, 1818
The False Angel Wing looks, of course, very similar to the real Angel Wing (Crytopleura costata). The False Angel Wing is about two inches long at maturity, and is chalky white. Ridges and ribs on the surface of the bivalve look a little like feathers — presumably like the wings of an angel. The “feathers” are wider on the anterior (front) end of the shell.
The major way to tell the False from the true Angel Wing is that the False Angel Wing lacks the spoon-like projection, the apophysis, which is located below the beak of the real Angel Wing. Of course, when you find a worn, weathered shell on the beach, it's hard to tell if “extra features” have been worn or broken off….
A further complicating factor in identification is that there exists, in the same general geographic area, the Campeche Angel Wing. The Campeche Angel Wing (Pholas campechiensis) has a curved shelly brace on the hinge side of the shell. This twelve-partitioned brace curves up over the outer surface of the shell. The False Angel Wing does not have such a feature.
To “muddy the waters” even more, there also exists the Fallen Angel Wing, Barnea truncata (Say, 1822). This member of the Piddock family lives intertidally in mud and peat banks from Massachusetts to Texas and Brazil. It is a fragile, elongated, white bivalve. The posterior end of the shell is truncated (squared off-looking). The posterior end has small, erect scales on it and ends almost in a point. The overall surface of the bivalve shell is incised with transverse and longitudinal wrinkles. The valves gape widely. To the front of the off-center beaks (umbones) of the valves there is a long shelly plate.
The Fallen Angel Wing has a thin grayish covering, the periostracum. The adult shell is approximately 2 inches long.
The adult False Angel Wing is usually 1½-2¼ inches across. The beak of the False Angel Wing is well elevated, and has a distinct lunule (a depressed area to the front of the beak).
False Angel Wings and their close kin live in shallow water. They burrow into stiff clay, mud, or peat. These Piddocks, and other members of their family, are, as conchologist Julia Rogers reported in 1901:
“Eaten, pickled in vinegar, on the Normandy coast; they are also cooked with fine herbs and bread crumbs. They are collected for food and for bait near Dieppe by women and children who use a special iron pick.”
Shell collectors may find False Angel Wings on beaches anywhere from Prince Edward Island southward down the East Coast of the United States and in the Gulf of Mexico. This species now may also be found on the West Coast and on some areas of the European coast.