THE CANADIAN ENTOMOLOGIST. 123 



The Hesperidae are regarded by me as a group equal in systematic 

 value to all the other Rhopalocera, and one which forms a transition to 

 the Heterocera. They approach the latter through the possession of an 

 attachment to the anterior tibiae, the double-spurred posterior tibiae of 

 most of the species, and in the pupa being enclosed in a net-work of 

 threads. No other group of the Diurnals, so far as I know, has two pairs 

 of spurs on the posterior tibiae. Besides the Hesperidae, the Papilioninae 

 (Equites) alone have the tibial epyphysis, and in these alone the thread- 

 enclosed pupa is found, at least in one of the genera (Parnassius). In 

 other respects, however, the Papilioninae are far removed from the 

 Hesperidse. 



The Hesperidae are still more decidedly characterized as a genealogical 

 transition group, between the Heterocera and the Rhopalocera, in that 

 they possess besides, in particular cases, two characteristic physiological 

 and anatomical peculiarities — the position of the wings when at rest, and 

 the catch-bristle ( haftborste ) of the hind wings. 



Nisoniadcs Tagcs carries its wings, as I have observed towards evening 

 in sleeping examples resting upon flowers, directed backwards and sloping 

 like the roof of a house, as in the night-moths. The same observation 

 had already been made by Prof. Zeller, not only in Tages, but in freshly 

 excluded examples of H. tnalvarum O., which last had the antennae placed 

 sideways and laid along the thorax, and the abdomen turned upwards, so 

 that the observer was reminded of a sleeping Heterogenea testudinana 

 (/sis, 1847, p. 288).. Whether others have also made the same obser- 

 vations with this or other species, I do not know. I have not myself 

 given the subject much attention. So far as I remember, I have always 

 found the other Hesperians, when at full rest, sitting with erect wings, in 

 the normal position of the Diurnals ; but not with separated wings, as has 

 been mostly stated. 



A fully developed retinaculum* occurs only in the male of Euschouon 

 rafflesiac Macleay, and it is remarkable that the home of this singular 

 genus is Australia, where so many primitive forms have been preserved 

 that elsewhere have been overthrown by terrestrial revolutions, or destroyed 

 by the concurrence of more progressive rivals. 



Looking away from these possibly single cases, the Hesperidae form a 

 very natural, in themselves closed, division of the Diurnals, and as such 



" [The frenulum of many authors. -L. | 



