SKINNER AND WILLIAMS 109 



ON THE MALE GENITALIA OF THE LARGER 

 HESPERIIDAE OF NORTH AMERICA 



BY HENRY SKINNER AND R. C. WILLIAMS, JR. 



It is now generally conceded that in some of the groups of 

 butterflies the male genitalia offer characters of very great 

 importance in classification. This was recognized as applying 

 particularly to the Hesperiidac by Godman and Salvin, who, in 

 the Biologia Centrali-Americana, give many excellent figures of 

 the Central American species, including many of those which 

 find their way into our fauna across the Mexican border. It is 

 our object in this paper to present figures of all the larger North 

 American species of which we have availa])le material. 



The Biologia, an unusually carefully prepared and scientifi- 

 cally correct publication is, however, not available to the average 

 student as the parts were not sold separately, and the three 

 volumes dealing with the Rhopalocera are now quoted separ- 

 ately at a very high ])rice. For this reason, and because the 

 details of the aedoeagus were omitted, we are again figuring the 

 Biologia species, although the correctness and excellence of 

 these figures commands our highest praise. 



Dyar in 1905^ reviewed the Hesperiidae, generall}' adopting 

 Scudder's classification; Skinner in 1911- contributed to our 

 knowledge of our larger species, and Lindsey's valuable paper 

 of 192P is the basis for our work, which covers the single species 

 in the sub-family Pyrrhopyginae and Group A of Dyar and 

 Lindsey in the Hesperiinae. 



Scudder in his "Butterflies of Eastei'ii United States and Can- 

 ada" has figured in volume III, ])late 35, the male genitalia of 

 five of the species of this group coming within the territory 

 covered by him. 



The genitalia were prepai'ed by separating the tegumen, 

 valvae and aedoeagus, and mounting them separately on slides; 



'Jour. N. Y. Ent. Soc, xni. p. Ill, 1905. 

 ^ Trans. Am. Ent. Sop., xxxvii, p. 159. 

 'Univ. of Iowa, Studies Xat. Hist., ix, no. 4. 



TKAXS. AM. EXT. SOC, XLVIII. 



