In a previous paper on the Siphonaptera of Canada the writer (Holland, 1949b) summarized all available published and unpublished data up to December 31, 1946. One hundred and twenty-seven species and subspecies of fleas were recorded, of which 121 are believed to be endemic, and 6 introduced in historic times from the Palaearctic Region.
Studies since 1946 have drawn attention to the occurrence in Canada of a number of species not hitherto recorded. Some of these were new to science. The discoveries of some of the others could have been predicted with reasonable certainty, the species being known from areas immediately south of the International Boundary, on species of hosts known to occur in Canada. In other instances the captures occasioned some surprise, the Canadian records representing rather broad extensions of the known ranges. Some of this supplementary information has already been published (Holland, 1949a, 1950, 1951a, 1951b). In the present paper, seven additional species and subspecies are reported from Canada for the first time. In partial compensation for this, the total of Canadian species is reduced by the recognition of two synonyms.