LEPIDOPTERA. 39 1 



yellow patch on the disk of the fore wing, and one of the 

 same color next the anal angle of the hind wing. 



This species is of unusual interest, as the larva is carniv- 

 orous in its habits. It feeds on plant-lice ; and, so far as 

 observed, it feeds only on the woolly aphids. It is found 

 more often in colonies of the Alder Blight {ScJdzoneura tes- 

 sellata) than in those of the allied species. It is found from 

 Maine to Northern Florida and westward to Kansas. It is a 

 very local insect, being found only in the neighborhood of 

 water where alder grows. 



II. The Blues, — The Blues may be distinguished from 

 the other gossamer-winged butterflies by the slender form 

 of the body, and the blue color of the upper surface of the 

 wings. About fifty North American species have been de- 

 scribed ; but most of these occur only in the far West. 

 This is a rather difficult group to study owing to the fact 

 that in several cases a single species exists under two or 

 more distinct forms, and also that the two sexes of the same 

 species may differ greatly. It often happens that two indi- 

 viduals of the same sex but of different species resemble 

 each other more closely in the coloring of the upper sur- 

 face than do the two sexes of either of the species. In 

 each of our eastern species the upper surface of the wings 

 of the female is much darker than that of the male. 



The Spring Azure, Cyaniris pseiidargioliis (Cy-a-niVis 

 pseud-ar-gi'o4us). — In this species the hind wings are with- 

 out tails, the eyes are hairy, and the lower surface of the 

 wings is pale ash-gray. This combination of characters will 

 distinguish it from all other blues* occurring in the Eastern 

 United States. But the species is not confined to this re- 

 gion, as it occurs in nearly all parts of the United States 

 and in a large part of Canada. 



This butterfly exhibits polymorphism to the greatest 

 degree of any known species ; nine or ten forms have been 

 described. Two of these are represented on Plate VI 

 (Figs. I and 7). 



The larva feeds on the buds and flowers of various 



