RILEY HACKBERRY BUTTERFLIES. 



Hackberry Butterflies. 



Descriptions of the early Stages of Apatura Lycaon, Fabr., and 

 Apatura Hkrse, Fabr. ; -with Remarks on their Synonymy. 



Bj Chas. V. Riley, M.A., Ph.D. 



One of the most beautiful of European butterflies, much coveted 

 and prized by the collector, especially in England, where it is ex- 

 tremely rare, is that known as the Purple Emperor (^Apatura Iris 

 'Fabr.) The wings in the male of this magnificent species exhibit 

 now the deep brown which alone the female, as a rule, possesses, 

 now a beautiful deep violet-blue, according to the direction from 

 which we view them. This changeability of color is owing to the 

 peculiar form, shape and arrangement of the wing-scales. If, by 

 the aid of a good microscope, we examine these scales, we shall 

 see that, besides the longitudinal imbrications so generally cha- 

 racteristic of the wing-coverings of the Lepidoptera^ they are 

 furnished, on the parts naturally exposed, with innumerable mi- 

 nute, transverse, angular ridges, each having a brown and each 

 a blue surface exposed — a fact which, by means of his excellent 

 magnifier, Rosel von Rosenhof demonstrated a century and a 

 quarter ago, and which at once explains the peculiarity which 

 renders the butterfly so conspicuous among its scaly-winged com- 

 panions. The adolescent life of this butterfly is quite inter- 

 esting, and there are amusing accounts of the zeal with which 

 the larva and chrysalis have been sought by some of the earlier 

 entomologists, and of the pleasure which their discovery has af- 

 forded. The larva feeds on Salix. 



In this country there are two butterflies belonging to the genus 

 Apatura, as heretofore understood, viz., Lycao?i Fabr. and Herse 

 Fabr. The complete natural history of these has so far remained 

 untold ; and from any figures or descriptions extant they could 

 not be distinguished from each other in their earlier stages. In 

 Boisduval et LeConte's Iconographie* to which we naturally look 

 for something respectable, the figures are, to speak in their own 

 language, aj^reuses. No characteristics are given by which the 



* Hist. Gen. ct Icon, des Lepid. et des Chenilles dc I'Ain. sept., 1833. 



iii — 13 ^ [Dec. 10, 1873.] 



