Sust. FEM. Barnacles. Lamelibranquio molluscum ( bivalve ) sifonado marino, of the family of the escalpélidos. Until well into the modern age, in Europe it was believed that some species of geese ( of the genus Branta ) they came from the barnacles. In English called barnacles both these cirrípedos ( 41 subclass; as those birds. It was a pretext to avoid the intake of meat during Lent, since - in Christianity-during this period the only food allowed were those of fish and seafood. So the bird of the same name that they and even other similar ( geese, ducks ) they classified as fish. Among the arguments for such curious taxonomy was the fact that the barnacles have appendices ( 41 extensions; similar to feathers and that deal with migratory birds, their nests or their offspring were not known. It's the Pollicipes pollicipes ( gender and species ). The diction is derived from the case «ánatis» of the nominative "anas" Latin genitive: pintails, duck. ( Information taken from Wikipedia and the encyclopedia of language, Martín Alonso )
