Abalone: popular name in the United States for a univalve gastropod mollusk of the genus Haliotis, members of which are also called ear shells, or sea ears, as their shape resembles the human ear. The shell provides a roof like covering for the abalone and is perforated by a row of holes on one side through which the animal respires. The iridescent mother-of-pearl shell lining is used to make buttons and other articles. Before protective legislation was enacted, much of the dried flesh and some shells were exported to Asia. Abalone are classified in the phylum Mollusca, class Gastropoda, order Archeogastropoda, family Haliotidae.