• Periwinkle (family Littorinidae)
Scientific classification
Kingdom:Animalia
Phylum:Mollusca
Class:Gastropoda
(unranked):clade Caenogastropoda
clade Hypsogastropoda
clade Littorinimorpha
Superfamily:Littorinoidea
Family:Littorinidae
Genus:Echinolittorina
E. ziczac or E. lineolata ?
Punta del Diablo, Rocha, Uruguay
via Flickr https://flic.kr/p/24Tbcfz