FAMILY BRUSH FOOTED BUTTERFLIES, 93 



a northern species, having in eastern America ahnost 

 precisely the range of AgJais milherti, and is fonnd in 

 forest roads and open woodhmd. It is probably single- 

 brooded and winters as a bntterfly, ajopearing fresh on the 

 Aving at the very end of June and early in July, but 

 becoming much more numerous later in the season and 

 hibernating in October, appearing again in the early spring 

 and laying eggs early in May. A swarm of this butterfly 

 invaded one of the Nantucket light-houses one September 

 night, perhaps in migration. 



15. Genus Poltgonia. 



The butterflies of this genus may be distinguished al- 

 most at a glance by their greatly angulated and excised 

 wings. All are tawny-colored above, heavily spotted and, 

 especially the hind wings, broadly bordered with black; 

 the dark markings of the fore wings consist mainly of two 

 stout bars depending from the costal margin and, around 

 I he inner bar, of a series of five or six rounded spots 

 arranged in a line bent at right angles, one limb parallel 

 to, the other depending from, the costal margin. The 

 species differ principally in the colorings and markings of 

 the under surface of the hind wings. 



POLYGONIA PROGNE— THE GRAY COMMA. 



(Vanessa progne, Grapta progne, Grapta c-argenteum.) 



Butterfly. — Middle of outer margin of fore wings distinctly 

 crenulate ; tail of hind wings not more than twice as long as 

 broad ; under surface of same wings gray, traversed by trans- 

 verse blackish threads, with sliglit greenish snbmarginal mark- 

 ings, and a central thin silvery L, the upper limb pointed at tip. 

 Expanse fully 2 inches. 



Caterpillar. — Head brown, crowned by long and slender 

 spines having lateral spinules thrown off from the middle, and 

 not so long as the portion of the central spine beyond them ; 



