periwinkle Littorina littorea, an edible mollusc living in a small single shell (up to 2.5 cm/1"), widely distributed on both sides of the N. Atlantic. Periwinkles, or winkles as their vendors commonly call them, are now eaten much more in Europe than America, although the middens of American Indians testify to their use there in the past. Prehistoric mounds in Denmark, Scotland, and elsewhere show that they have been a popular European food for a very long time; and the diversity of vernacular names, such as kruuk’ls in Zeeland, points to continuing popularity in more recent centuries. Now, however, they are becoming a grander food, being served as amuse-gueules in expensive restaurants.