195 



XIX. The two Principal Groups of Urbicolae 

 (Hesperidae auct.) 



BY SAMUEL 11, SCCDDER. 



[Read before this Society, December 19, 1873.] 



The classification of the Urbicolae (Hesperidae auct.) has proved 

 a stumbling-block to all who have proposed any arrangement of 

 butterflies. No author, Hiibner excepted, has even attempted more 

 than a generic collocation, and the two most recent essays of this 

 sort have been exceedingly unsatisfactory. In his Verzeichniss, 

 Iliibner divided the "stirps" into eight "families;" the first three 

 of these are founded mainly on the form of the wings, the others 

 simply on their markings; these divisions are almost wholly unnat- 

 ural, although the sequence of the genera is far more reasonable than 

 that of Herrich-Schaeffer or Butler. 



Fabricius was the first to separate the family into distinct genera. 

 In liliger's Magazine he divided it into three genera — Thymele, 

 Helias and Pamphila. Helias was founded upon a single, unde- 

 scribed and now unknown species. If w^e omit Helias, the genera 

 Thymele and Pamphila will represent in the main* the natural 

 separation of the Urbicolae into two grand divisions, which are of 

 less value than sub-families, and may therefore be termed tribes; 

 to the former we may apply the name Hespcridcs, which Latreille 

 gave in 1807 to the whole family, since it includes the genus Hes- 

 peria; w'hile the other may retain Hubner's name Astyci (1816), 

 formerly intended for the wiiole group. 



The following distinctions will be found between the two tribes : 



In the Hesperides, the fore wing of the male is always provided 

 with a costal fold where a sort of silky down is concealed; this 

 feature is often very inconspicuous; in the Astyci, on the other 

 hand, the male is generally furnished with a discal patch of pecul- 

 iar scales crossing the median interspaces of the fore wings, iisually 

 in an oblique direction ; but sometimes the wing of the male is as 

 simple as that of the female. In the male Hesperides again, the 



* Some species enumerated under Pamphila belong to the first division. 



