I recently went snorkeling when the surf was unusually small on the North Shore. The water was so cold I later looked up January’s water temperatures for Oahu: 75 to 76 degrees. Not exactly polar weather, but combined with the cool air, it was enough to make Hawaii residents reluctant to get in the water. (Our warmest water, 80 degrees, occurs in September.)

I pulled my wet-suit jacket over my chicken skin, plunged into the ocean and, as usual, was rewarded for the effort. I found, for the first time ever, a striking orange-and-white miter shell rolling around on the ocean floor.

Because the shell appeared to be empty, I made the mistake of putting the lovely thing in my pocket and swimming on.

Miters are a family of snails that create attractive, spindle-shaped shells, thick in the middle, tapering at each end. About 500 species exist, mostly in the Indian and West Pacific oceans. Hawaii hosts 49 miter species. Of those, which range in size from 1 to 7 inches long, eight are endemic.

All miter snails are carnivores. They eat worms, clams and other snails, dead or alive. If the prey is alive, the miter kills it with a venomous sting.

The snail I found is a beauty called the episcopal miter, the largest of all miters. Some miters live on rocks and in rubble, but the episcopal miter buries itself in the sand on the ocean floor from several to hundreds of feet deep. While lurking under the sand, the predator can sting unsuspecting prey passing overhead.

The scientific name of the episcopal miter is Mitra mitra. Its common name, episcopal, comes from someone’s notion that the shell looks like an episcopal bishop’s hat, called a miter or, in England, a mitre.

The idea caught on. In his book “Hawaii Seashells,” Mike Severns names, in addition to the episcopal miter, a papal miter and a pontifical miter. To me the resemblance of these snails to Christian clerical headgear is far from clear.

After my shivery swim, I stood under a hot shower, peeled off my shorts, and there in the back pocket found my shell. Oh, no. Its little snail peeked out, likely suffocating in the freshwater stream.

The snail didn’t sting me (I don’t know whether miter snails can penetrate human skin), but if it had, I deserved it. I had been too hasty to get out of the chilly water and didn’t give the snail time to show itself. I apologized to the snail and rushed it back to its ocean home.

Later, on the evening news, I watched subzero blizzards batter the mainland and felt extra grateful that I live in Hawaii — even when the temperatures get all the way down to the bone-chilling 70s.

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