A Revision of the Nearcticameletusmayflies Based on Adult Males, With Descriptions of Seven New Species (Ephemeroptera: Ameletidae)

A systematic revision of North American species of the genusAmeletus, excluding parthenogenetic species, is presented. Seven new species are described (A.andersoni,A.bellulus,A.doddsianus,A.edmundsi,A.majusculus,A.pritchardi, andA.tolae), separate keys are given to western and eastern species, annotated accounts of all 30 presently recognized bisexual species are provided, taxonomic characters are illustrated, and distribution data are presented for all species. The following nomenclatural changes are proposed:Ameletus aequivocusis considered a junior synonym ofA.sparsatus; A.alticolusandA.celeroidesjunior synonyms ofA.celer;A.connectinaandA.connectusjunior synonyms ofA.velox;A.facilisa junior synonym ofA.vancouverensis;A.montaa junior synonym ofA.similior;A.querulusa junior synonym ofA.shepherdi. The specific status ofA.tuberculatusis questioned and it is provisionally considered to be the same asA.celer.