Abstract
Characters of the opercular and parietal calcareous plates are commonly used in formulating barnacle descriptions and discussing their taxonomy. However, in some groups these characters have created taxonomic confusion due to a high level of intraspecific variability. We redescribe the shallow-water balanomorph barnacles from Bahía de La Paz in Mexico for which the original descriptions were incomplete or did not include the arthropodal parts. The descriptions present here are based on classical characters derived from calcareous plates (external features) as well as internal characters derived from flexible cuticular body parts such the cirri and parts of the oral cone. The latter character set proved helpful in resolving taxonomic confusion among some of the barnacle species studied. Detailed redescriptions of three species from three genera are presented, along with remarks on their distribution ranges.
