Abstract
Laonice species from South and Central America are reviewed based on museum collections and new material collected in southern Brazil. An identification key is provided to 10 species including three previously described species, L. antarcticae Hartman, 1953, L. weddellia Hartman, 1978, L. branchiata Nonato, Bolívar & Lana, 1986, and three species represented by poor material, insufficient for final taxonomic diagnosis. Four new species, L. petersenae sp. nov., L. aperata sp. nov., L. parvabranchiata sp. nov., and L. pinnulata sp. nov. are described and illustrated. Earlier records of L. cirrata (M. Sars, 1851) from South America are not confirmed. The loss of neuropodial sabre chaetae and hooks until a certain size in terms of numbers of adult chaetigers is here used for the first time as a specific character with Laonice species.