Littorina plena

''Littorina plena'' is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles.{{WRMS species|445659|''Littorina plena'' Gould, 1849|||Reid, David G. . Littorina plena Gould, 1849. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=445659 on 6 June 2010}}