Seashells of North Carolina. By Hugh J. Porter and Lynn Houser. Photography by Scott D. Taylor. North Carolina Sea Grant College Program, 132 pages, $12.00.

There are shells that can make you feel lucky—rare favorites, or beautiful strangers discovered in an afternoon’s stroll. Hugh Porter favors the wentletrap, a shell that looks something like a lemon ice spiraled into a cone.

Seashells of North Carolina tells us that at least 24 variations of the wentletrap have visited our beaches. Most of those shells, Porter has collected. He’s a coauthor for the recently revised and reprinted seashell guide, and he’s been beachcombing the North Carolina shore since the 1950s, beginning and maintaining the university’s extensive mollusk collection as curator and collector.

Of the three million specimens in the collection, 261 species made it into the guide. More common shells made the cut, and it helped if the shell were large enough to easily spot. Still, deciding was hard for Porter: “I kept adding shells, until my editor finally said, `no more.’”

Like most guides, this one includes photos and information about each shell. But it’s not just a lexicon. It includes lectures on shell identification, and on the best methods of collecting and identifying the shells. The lessons go down easy—they’re written for anyone with an interest in mollusks.

Mollusks, the guidebook reminds us, are soft-bodied animals with external skeletons, or shells, that protect their fleshy parts. Their armor is our treasure trove. We expect to find them as we walk the beach, but a few of these animals are deep-sea dwellers, accessible only to divers. Other mollusks prefer estuaries.

The estuarine shells can show up in unexpected places, says Porter—appearing on pilings, or attached to the underside of floating docks, favored by mollusks that like hanging out in the shade.

But mollusks aren’t always so happy with our encroachment. Porter suspects that development and channel dredging may be bad news for certain shell species.

Just after the Civil War, as shell collecting came into fashion, a surgeon at Fort Macon penned several articles about the molluskan fauna of North Carolina. In one, he noted that it was difficult to take a step without crushing the shell of the wentletrap.

Today, Porter says, you’re lucky to find even one.

Julia Bryan was formerly a staff writer for Endeavors.