Noun
One of the classes of Mollusca, of great extent. It includes most of the marine spiral shells, and the land and fresh-water snails. They generally creep by means of a flat, muscular disk, or foot, on the ventral side of the body. The head usually bears one or two pairs of tentacles. See Mollusca.
Source: Webster's dictionaryThe venomous cocktail of the vampire snail Colubraria reticulata (Mollusca, Gastropoda). Source: Internet
Euthecosomata, a group with remarkable developmental stages (Gastropoda, Pteropoda). Source: Internet