THE GENUS HESPERIA. 93 



The Genus Hesperia.* {With plate.) 



By T. A. CHAPMAN, M.D. 



The appearance of this "Eevision " by Dr. Reverdin may be taken 

 as a completion and summary of the researches in this genus, which 

 he has been making for a long time. The first article published seems 

 to have been that on the malvae group, in 1910, in the Bulletin of the 

 Lepidopterolof/ical Society of Geneva, and in that medium his various 

 papers have been published since, though he has also collaborated with 

 M. Oberthiir in the LSpidoptSrologie Com.patee. This seems, therefore, 

 to be a fitting time to give in the Ent. Record some account of the 

 results obtained. 



Dr. Reverdin depends in- the main on the morphological differences 

 in the male appendages of the various species, both for distinguishing 

 those that are specifically distinct, and for recognismg what the re- 

 lationships are between them. He nevertheless in most cases makes 

 an elaborate study of other characters, but in not a few cases with the 

 result that he finds nothing so definite as to enable him to rely on the 

 characters observed without reference tp the study of the male arma- 

 ture. He nevertheless nearly always finds that the conclusions to be 

 derived from these are supported, positively or negatively as the case 

 may be, by the wing markings, or other structures, habits, etc, of the 

 forms being studied. 



It is well known that Rambur, some 80 years ago, made researches 

 in this direction in regard to the Hesperias of Andalusia, and arrived 

 at conclusions which, though partial and founded on a technique much 

 less complete than is now usual, nevertheless as far as they go, stand 

 good at the present time, although in the interim they have been 

 neglected, pooh-poohed, and despised by Entomologists, who, we fancy, 

 ought to have known better, as for example Frey, who lumps species 

 together freely. 



Dr. Reverdin's first paper (1910) gives an introduction to the 

 subject and a resume of the positions, and a detailed account of the 

 structure of the male appendages in the genus. As our own interpre- 

 tation of these structures is substantially the same as Dr. Reverdin's, 

 it may conduce to brevity and clearness merely to point out the general 

 nature and appearance of these structures, without too much insistence 

 on details. For this purpose it may be well to begin the consideration 

 of the matter by referring to what is probably the least specialised 

 example. 



But, first, it is necessary to say that the specimens examined have 

 all been prepared in the manner adopted by Dr. Reverdin, viz., remov- 

 ing one clasp so as to expose the remaining parts without serious over- 

 lapping, the only difference being that the removed clasp is usually not 

 quite separated, but sufficiently so to be folded back, and when actually 

 separated is mounted with the clasp in as nearly such a position as 

 may be. 



Hesperia carthami may be assumed to be the species with the least 

 specialised appendages. Assumed, because though there are reasons 

 for the assumption, they cannot claim to be in any way proofs, and 



* Eevision du Genre " Hesperia " (Especes palearctiques) par le Professeur J. L. 

 Eeverdin de Geneve, in Etudes de Lepidopterologie Compar^e, vol. xii. 

 May 15th, 1917. 



