It was cause for shell-ibration, if not rapture, when I found a special shell on an Island beach. 

The specimen — or part of one — was an angel wing, perhaps a sign from above but more likely one from below. This was not a guardian angel though because of its scarcity, I found myself guarding it like a treasure.

Angel wings are unusual finds on our beaches. If you want to obtain one on the Vineyard, your best bets are south shore beaches, specifically the coasts of Tisbury Great Pond and Squibnocket. This is the advice found in Richard and Holly Heuer’s classic book, Exploring for Sea Shells on Martha’s Vineyard. We are at the northern edge of the range for pholadidae, this particular family of clams that bore into the seabed. They are also known as boring clams — though they are anything but boring.   

Their common name alludes to their usually white shell halves, though they are sometimes pink because of the algae they filter and eat. When open, the shell halves resemble the wings of an angel. The shells are delicate and break easily when they come to the surface and get tossed about.

More detrimental to their side by side union is that the muscle that holds the valves together is weak, so the shells will separate easily during the clam’s life and, more so, in death, when the muscle deteriorates leaving only the shell halves behind. 

The family pholadidae includes a variety of species including angel wings, false angle wings, fallen angel wings and piddocks (which buck the angel-naming convention). 

This family was described by wild food enthusiast Euell Gibbons as the “most beautiful and delicious of all clams.” He also noted the difficulty he encountered in procuring them, explaining: “They have to be good to repay the arduous labor that is expended in collecting them.” Mr. Gibbons made these declarations while on a Cape Cod clam collecting quest inspired by Rachel Carson, who had written about digging these bivalves from a Buzzards Bay mud bank.

Across the sea, the French were also known to partake of this marine morsel. Conchologist Julia Rogers reported at the start of the 20th century that angel wings were “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.” 

The difficulty in procuring angel wings and other mollusks in their family springs from their depth below the sea and the substrate in which they prefer to reside. Despite their placid and ethereal appearance, angel wings can vigorously dig themselves down, way down, going as far as six feet below the surface. For a human, that would be equivalent to digging down to subway level or below, through compacted mud. These mollusks are found in hard clay and even soft rock. 

It is quite a trick to master drilling down into such hard habitats. Angel wing shells have a collection of raised spines called radial riblets that aid in penetrating rock — and even wood or concrete — as the animal revolves its body to provide even more downward force. 

 Though they are powerful when pirouetting, they become weak when left without the strong clam muscles that so delighted Euell Gibbons. Angel wings do remain influential in death with their scarcity. So I felt myself fortunate to find a piece of an angel, like a treasure from the heavens.

Suzan Bellincampi is Islands director for Felix Neck Wildlife Sanctuary in Edgartown and the Nantucket Wildlife Sanctuaries. She is also the author of Martha’s Vineyard: A Field Guide to Island Nature and The Nature of Martha’s Vineyard.