6 MB. E. Y. ■\VATSOy OS THE HESPERIID.I. [Jail. 17, 



as Hesperiidse ; the Australian genus Euschemon, winch is furnished 

 ■with a frenulum, one of the most distinctive characters of the 

 Heterocera, has also been omitted ; should subsequent authors 

 consider tliese three genera are more naturally placed in the 

 Hesperiidse, it will be necessary to establish two additional sub- 

 families for their reception. 



"With regard to the vexed question of the generic importance of 

 male secondary sexual characters, the conclusion which has been 

 forced upon me is that, in any particular genus in which male 

 secondary characters are found, the particular male character (be it 

 costal fold, discal stigma, or tuft of hairs) may be either present or 

 absent in different species of that same genus, but is never replaced 

 by a character of different structure. Of the inconstancy of the 

 male character in the same genus the following are examples : — 

 Eudamus, Thoryhes, Hesperia, Lrbanus, Ismene, liasora, Kerana^ 

 Padraona, Taractrocera, Chapra. Baoris, Ilalpe, and many others 

 might be brought forward ; but on the other hand it is difficult to 

 quote a single genus in which the male character is re})laced by 

 another of similar character, and in a few cases where this is appa- 

 rently the case in the following paper, it is owing to new genera not 

 having been erected for the aberrant forms though manifestly 

 distinct, time not allowing of the critical examination necessary. 



On every other occasion when the male secondary character differs 

 in structure, an accompanying difference will be found in the neura- 

 tion, antennee, or other point of structure. 



The above being the case, the costal fold, discal stigma, or other 

 structural ])eculiarity of the male insect, though frequently not a 

 generic character, is vet of the greatest importance in the formation 

 of grou}.s or subfamilies, and, as has already been pointed out by 

 Scudder, all those species which are provided with a costal fold 

 belong to the Jlesjje/ibio', and all those provided with a discal stigma 

 to the Pump/ulinfc 



Though the above conclusion is not in accordance with the theory 

 of many authors, yet it will be found that no author can be quoted 

 who does not admit it in practice ; for instance, Scudder places 

 hathyllns and pylades in the same genus Tliorybes, thougli the 

 former is without a costal fold and the latter is provided with one; 

 Mabille, in his paper above quoted, includes in the genera Thymele, 

 Eudamus, ^EthlJla, Ismene, Pumphila, and others species both pro- 

 vided with and devoid of male secondary characters; Moore, wliois 

 one of the strongest advocates for the generic importance of male 

 characters, yet, under the same generic name Thanaos, describes 

 indistinctu and stigmata, tlie former of which lacks the discal stigma 

 of the latter, includes in his own genus Hcdpe the species ladians, 

 though without the discal band chaiacteristic of the genus, describes 

 afJcinsoni, suhtestaceus, nilfjii-iana, and vindhiana, all as belonging 

 to the genus Isoteinon, though the two former possess a tuft of hairs 

 on the fore wing which is wanting in the latter, and acts similarly 

 on several other occasions ; while Distant and Trimen in their re- 

 spective works allow to male characters no generic importance 



