What is "littorina"

Littorina \Lit"to*ri"na\, n. [NL. See Littoral.] (Zo["o]l.) A genus of small pectinibranch mollusks, having thick spiral shells, abundant between tides on nearly all rocky seacoasts. They feed on seaweeds. The common periwinkle is a well-known example. See Periwinkle.

Littorina is a genus of small sea snails, marine gastropod molluscs in the family Littorinidae, the winkles or periwinkles.

These small snails live in the tidal zone of rocky shores.