Genus Argynnis 
nervule. The hind wing has a well-defined precostal nervule; 
the cell in this wing is closed by a moderately thick lower disco- 
cellular vein, which joins the median exactly at the origin of the 
second median nervule. The fore feet of the males are slender, 
long, and finely clothed with hair. The fore feet of the females 
are of the same size as those of the males, but thin, covered with 
scales, and only on the inner side of the tibiae clothed with mod¬ 
erately long hair. 
Egg -—The eggs are conoidal, truncated, and inwardly de¬ 
pressed at the apex, rounded at the base, and ornamented on the 
sides by parallel raised ridges, not all of which reach the apex. 
Between these ridges there are a number of small raised cross¬ 
ridges. 
Caterpillar. — The caterpillar is cylindrical, covered with spines, 
the first segment always bearing a pair of spines somewhat 
longer than the others. All of the species in North America, so 
far as their habits are known, feed upon violets at night. During 
the daytime the caterpillars lie concealed. 
Chrysalis .— The chrysalis is angular, adorned with more or 
less prominent projections. The head is bifid. 
The genus Argynnis is one of the largest genera of the brush¬ 
footed butterflies. It is well represented in Europe and in the 
temperate regions of Asia, some magnificent species being found 
in the Himalayas and in China and Japan. It even extends to 
Australia, and recently two species have been discovered in the 
vicinity of the great volcanic peak, Kilima-Njaro, in Africa. But 
it has found its greatest development upon the continent of North 
America. The species composing this genus are among our most 
beautiful butterflies. Owing to the fact that there is a great ten¬ 
dency in many of the forms closely to approximate one another, the 
accurate distinction of many of the species has troubled natural¬ 
ists, and it is quite probable that some of the so-called species will 
ultimately be discovered to be merely local races or varietal forms. 
The species that are found in the eastern part of the United States 
have been studied very carefully, and their life-history has been 
worked out so thoroughly that little difficulty is found in accu¬ 
rately determining them. The greatest perplexity occurs in con¬ 
nection with those species which are found in the region of the 
Rocky Mountains. While silvery spots are characteristic of the 
under side of most of the fritillaries, in some species the silvery 
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