94 
NYMPHALIDAE 
out Europe (except the extreme south), northern Asia to 
Amurland. 
Time of Appearance. The average time of appearance for 
this butterfly is about the middle of May, and it remains on 
the wing until the middle of June. In early seasons it is 
out during the latter part of April. 
In 1893 it was well on the wing by 
mid-April, and in late seasons I 
have often met with it in July. 
In this country it is single brooded, 
but in exceptionally warm summers 
specimens of a second brood have 
been recorded. In 1893 the con¬ 
tinuous warmth induced a few 
larvae of a brood I had under obser¬ 
vation to feed up abnormally and 
pupate, resulting in the butterflies 
emerging in August, while the rest 
of the brood of larvae entered into 
hibernation in July, during the 
hottest weather. 
Hibernation. A . cuphrosyne hi¬ 
bernates in the larval state. 
Egg Laying. The eggs are laid 
singly on the leaves and stems of 
the Dog Violet (Viola canina) during the latter part of May 
and early in June. The egg state lasts from ten to fifteen 
days, according to the temperature. 
Egg. The egg is o*8 mm. high, of a conical shape and is 
traversed longitudinally by about twenty-five keels, the 
spaces between the keels are transversely ribbed. The egg 
is greenish-ochreous-yellow when first laid, changing to pale 
yellow and finally to whitish-ochreous with a leaden-grey 
crown produced by the dark head of the larva showing 
through the shell just before hatching. 
Larva. The larva usually enters into hibernation about 
the end of July after its third moult, and measures 10*5 mm. 
long. It usually selects for its hibernaculum a dead crumpled- 
up leaf, settling down on the under side. I found the plants 
which were most subjected to the cold and wet appeared 
Sixth and seventh seg¬ 
ments of larva of the Pearl- 
bordered Frit illary on emer¬ 
gence from the egg. 
