Webster’s Revised Unabridged Dictionary · 1913
Littorina
Lit′to·ri′na (lĭt′tō·rī′nȧ), n. [NL. See Littoral.] (Zoöl.) 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.