Forty-Two Hitherto Unrecognized Genera and Subgenera of Zygoptera

During the past five years the writer has been engaged in a revision of the genera of the Zygoptera. The following new genera and subgenera have been in manuscript form for from two to five years. In nearly every case the characters of the penis have been the primary indicators that a new generic term might be advisable. In nearly every case other characters, usually venational, were found to parallel the penis characters. The writer has attempted to give the genus a value which as nearly as possible represents the same amount of differences in whatever part of the Zygopterous series it might fall. This ideal was not altogether attainable, because genera have been split so very fine in the Agrioninas and some of the other very modern groups. Even in these groups, however, the genera are not as close as in some sections of the Libellulidas, where connecting links have not yet dropped out. No apologies are offered for the series of monotypic genera. These in nearly all cases are annectant forms, the last fragments of faunas preceding the present. Pull descriptions of these new genera and subgenera with an extended discussion of their relationships as shown by the genitalia will eventually appear, the author hopes, as a bulletin of the U. S. National Museum.