NATURE NEWS Three kinds of periwinkles live in Gulf of Maine Photo by Sue Pike The common periwinkle is considered an invasive non-native species in the Gulf of Maine. A rough periwinkle is at the bottom, smooth periwinkle in the middle and the relatively huge common periwinkle in back By Sue Pike yorkweekly@seacoastonline.com Posted Jul. 19, 2016 at 5:02 PM There is one local snail that I would bet everyone who lives in coastal New England knows and loves: the common periwinkle. What young person hasn’t picked up a periwinkle from the beach and tried to hum it out of its shell? Who doesn’t think that these are cute snails? If you have been to a local beach and your eyes were open, you undoubtedly saw at least one periwinkle — given how many there are out there they are hard to miss. What most people don’t know is that there are three snails that live in the intertidal zone in the Gulf of Maine that go by the name "periwinkle." The one most of...