Taxonomic Studies on the Ephemeroptera. II. The Genus Hexagenia

Abstract

The hexagenids are the ephemerids that first attracted my attention to the order Ephemeroptera. Ever since 1927, I have been gradually accumulating data with the specific intention of revising as thoroughly as possible this highly important and abundant genus. During the past year, efforts have been made to see the type specimens and to compile distributional data concerning each species and subspecies. I have seen the material in the British Museum (Natural History) (B.M.), the Canadian National Collection (C.N.C.), the Cornell University Collection (C.U.), the Illinois Natural History Survey (IS.), the Museum of Comparative Zoology (M.C.Z.), the Museum of Zoology of the University of Michigan (U.M.), the Ohio State University Collection (O.S.U.), and the Oklahoma Natural History Survey (O.S.), as well as the private collections of Professor Fred Ide (Ide), Dr. Earle Lyman (Ly.), and Mr. W. T. Davis (Davis). The letters or names in parentheses as given above are the respective abbreviations that are utilized in the distributional data which accompany each species or subspecies. In addition, the collection of the American Museum of Natural History (A.M.N.H.) and my own collection have been available. Dr. William Upholt has loaned me paratypes of his Hexagenia limbata californica as well as having sent other material.