1) Family littorinidae 2) Mollusk family 3) Periwinkles 
The Littorinidae are a taxonomic family of over 200 species of sea snails, marine gastropod molluscs in the clade Littorinimorpha, commonly known as periwinkles and found worldwide. ==Names== In English-speaking countries of other parts of the world, gastropod molluscs from other families, such as the Neritidae, are sometimes also commonly known a...
[n] - periwinkles
family Littorinidae noun periwinkles