Small edible marine snail; steamed in wine or baked.
Sounds about as appetizing as the jellied eel, IMO. But fellow WordPress.com blogger J P Waldron (who posted the photo above) has advice for foraging them, and a recipe, if you’re feeling adventurous.
A familiar figure stepped out from the flare around a jellied eel stall, holding a plate of winkles. THE VINEGAR IS PARTICULARLY PIQUANT. HELP YOURSELF, I HAVE AN EXTRA PIN.