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 (Schizoneura 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 pseudargiolus (Cy-a-ni'ris 
pseud-ar-gi'o-lus).—In this species the hind wings arc 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. 1 and 7). 
The larva feeds on the buds and flowers of various 
