The Neotropical land snails (Mollusca, Gastropoda) collected by the 'Comisión Científica del Pacífico'

The land snails collected by the 'Comisión Científica del Pacifíco' (CCP), a Spanish expedition to South and Central America from 1862-1866, are restudied and revised. The historical context of the expedition and the study of its collected material are described. Biographical data is given for the main persons involved. The land snails were previously studied by Joaquin Hidalgo between 1867 and 1893. A total of 3,470 specimens belonging to 211 species are treated in this paper. Of 34 species mentioned by Hidalgo is his catalogue, the corresponding material could not be located. Hidalgo, 1869 is now placed in the genus Pilsbry, 1896, a new combination.