404 THE STUDY OF INSECTS. 



wings, and by the presence of a whitish spot on both fore 

 and hind wings, near the apex, and between two larger 

 black patches. On the lower surface of the hind wings 

 there is a small L-shaped silvery bar. This species occurs 



Fig. 477. — Eugenia j-album. 



throughout Canada and the northern portion of the United 

 States east of the Rocky Mountains. 



Polygonia (Pol-y-go'ni-a). — The butterflies of this genus 

 resemble the preceding species in having a metallic spot on 

 the lower surface of the hind wings, but differ in having the 

 inner margin of the fore wings roundly notched beyond the 

 middle. Nearly a dozen species occur in this country. 

 These differ principally in the coloring and markings of the 

 under surface of the hind wings. The following are some 

 of the more common ones : — 



The Green Comma, Polygonia /annus (P. fau'nus). — The 

 silvery mark of the hind wings is usually in the form of 

 a C or a G, the ends being more or less expanded (Plate VI, 

 Fig. 2), but sometimes it is reduced to the form of an L. 

 The lower surface of the wings is more greatly variegated 

 than in any other species of this genus ; and there is a larger 

 amount of green on this surface than in any other of the 

 eastern species, there being two nearly complete rows o' 

 green spots on the outer third of each wing. 



The larva feeds upon black birch, willow, currant, and 



