128 THE COMMONER BUTTERFLIES. 



pale-green eggs are shaped like a tiny sea-urchin and are 



laid singly on the seed-pods of the food-plants, Polygonum 



and Rumex. 



31. Genus Epidemia. 



EPIDEMIA EPIXANTHE— THE PURPLE DISK. 



(Polyommotus epixanthe, Chrysoplianus epixanthe, Lycaena epix- 



anthe.) 



Butterfly. — Upper surface of wings dark brown, the male hav- 

 ing a burnished chocolate tint with violaceous reflections on the 

 basal half, with three or four blackish dots on the disk. Under 

 surface pale straw-yellow with blackish markings, heavier on the 

 fore than on the hind wings, similar to those of Chrysoplianus 

 thoe, and on the hind wings a marginal series of slight orange 

 lunules. Expanse fully 1 inch. 



Caterpillar and Chrysalis unknown. 



This is a very local butterfly, found only in peaty 

 meadows, but there often very abundant. It is found 

 all over New England and its borders and near the Cana- 

 dian boundary westward to the Great Lakes and beyond, 

 but its distribution there is imperfectly known; it is said 

 to have been taken in Kansas. It seems to be single- 

 brooded, appearing at the end of June, continuing to 

 emerge from the chrysalis until beyond the middle of July 

 and flying until the end of the first week in August. The 

 eggs, which are very similar to those of Chrysoplianus thoe, 

 are laid in July, singly, and apparently do not hatch until 

 the next season. The caterpillar will i^robably be found to 

 feed upon some dock or knot-weed. 



Two other species of Epidemia inhabit our district: E. dorcas, found 

 in its northernmost limits, and E. helloides, a Pacific coast species re- 

 ported to be found in Iowa. 



32. Genus Heooes. 



HEODES HYPOPHL.kAS— THE AMERICAN COPPER 



(Cbrysophanus hypophlaeas, Chrysophanus americanus.) 

 Butterfly. — Upper surface of the fore wings fiery red, the outer 

 border blackish brown; this is reversed on the hind wings, though 



