The status of the generic names Erythemis, Lepthemis, and Mesothemis (Anisoptera: Libellulidae)

The most recent paper I am aware of in which the merits of Erythemis, Lepthemis, and Mexothemis are discussed as of generic or subgeneric rank is that of C.H. KENNEDY ( 1923. Mine. Puhl. Mux. Zuol. Unix. Mich. Il: 19-22. pi. I. figs 7-16). His suggested possibilities are based primarily on his study of the penis. He made no final decision for a synonymy as is evident by the following: "The American species, by penis characters, divide into four groups which are exactly equivalent with the groups as outlined by [P.P ] CALVERT [1901-1908, Otlonaia. Biol. Ceni.-americana, Porter & Dulau, London] and [F] RIS [ 1911 .Colins :ool. tie Selys 12: 529-700] on other characters. To these. Rhodothemis rufa may be added as an extra group. In the key I have placed it first as Group I because of its generalized characters. The fifth and largest group is composed of species with penes so much alike that no good characters appear on which to divide them further, though they seem to fall into two subgroups on the shape of the abdomen. The writer would be inclined to call the whole series of five or six groups Lepthemis and would consider the individual groups as subgenera, which could be given generic rank by those who wish to use smaller genera. Lepthemis, for the whole series Irom Rhodothemis rufa to Erythemis haematogastra, is no more comprehensive, in the writer's opinion, than Libellula for the series of species included in the latter by Ris and later by the writer. The comprehensive genus would have to be Lepthemis because of the priority in the use of that name." [By page priority only]