A cladistic analysis based on 21 characters from the external morphology and male genitalia was undertaken in order to determine the status of the flea subgenera Ctenophthalmus (Alloctenus) and C. (Nearctoctenophthalmus). As a result of the analysis, Ctenophthalmus (Alloctenus) (=Nearctoctenophthalmus, new synonym) comprises nine species (in phylogenetic sequence): C. pseudagyrtes, C. sanborni, C. micropus, new status (from subspecies of C. pseudagyrtes), C. haagi, C. tecpin new species, C. caballeroi, C. cryptotis, C. expansus, and C. myodosus, new status (from subspecies of C. expansus). Biogeographic data indicate that two species (C. pseudagyrtes and C. micropus) are widespread in both the Nearctic and Neotropical regions, another (C. tecpin) is exclusively Nearctic, whereas the remaining six species are exclusively Neotropical. Within the latter, the monophyletic clade including those species previously assigned to C.(Alloctenus) is endemic to the Transvolcanic Mexican Belt. Host data indicate that the most primitive species are basically parasites of sigmodontine mice (Rodentia: Muridae)—secondarily associated with Talpidae and Soricidae (Insectivora)—whereas the most derived species are exclusive parasites of the shrew genus Cryptotis (Insectivora: Soricidae).