Abstract
Description of, and keys to, 10 species of Lepeophtheirus (Copepoda:Caligidae), parasitic on fishes of British Columbia, are given. Diagnostic value of different morphological details is discussed. Nine of the species included were previously known (L. bifidus, L. breviventris, L. hospitalis, L. nanaimoensis, L. parvicruris, L. parviventris, L. paulus, L. pravipes, and L. salmonis) and one is described for the first time (L. oblitus).