Genus Thorybes 



Genus THORYBES, Scudder 

 (The Dusky-wings) 



Butterfly. — The club of the antennae is not very heavy, hooked, 

 the hooked portion about as long as the rest of the club. The 

 palpi are directed forward, with the second joint heavily scaled, 

 and the third joint very small. The fore wing 

 may be with or without the costal fold in the male 

 sex. The cut gives a correct idea of the neuration. 

 The hind wing is evenly rounded on the outer 

 margin, sometimes slightly angled at the extrem- 

 ity of the submedian vein. 



Egg. — The egg is subglobular, somewhat flat- 

 tened at the base and on top, marked with numer- 



Fig. 1 55- — ous fine and not much elevated longitudinal ridges. 

 Neuration of the _, . , ., _ . .. 



genus Thorybes. ' ne micropyle covers the upper surface of the egg 



and is not depressed. 



Caterpillar. — The caterpillar somewhat resembles that of the 

 genus Epargvreus, but is relatively shorter, the head proportion- 

 ately larger and more globular. The neck is greatly strangulated. 



Chrysalis. — The chrysalis is somewhat curved in outline, with 

 a strongly hooked cremaster and a prominent projection on the 

 back of the thoracic region. 



(i) Thorybes pylades, Scudder, Plate XLVIII, Fig. 6, $ ; 

 Plate II, Figs. 25, 29, larva; Plate VI, Fig. 28, chrysalis (The 

 Northern Dusky-wing). 



Butterfly. — The upper side is represented correctly in Plate 

 XLVIII. On the under side the wings are dark brown, shading 

 into hoary-gray on the outer margins. The hind wings are 

 crossed by irregular basal, median, and postmedian brown bands 

 of darker spots, shaded with deeper brown internally. The 

 translucent spots of the upper side reappear on the lower side of 

 the fore wings. Expanse, 1.60 inch. 



Early Stages. — These are elaborately described in the pages of 

 Dr. Scudder's great work. The caterpillar feeds on clover, Les- 

 pede^a, and Desmodium. 



This insect is found throughout the United States and Canada, 

 but is not as yet reported from the central masses of the Rocky 



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