NYMPIIALINAE : TIIK (iEXUS AGLALS. 417 



pears ahout the middle of fliiiie, the seeinid in the hitter part of July, and 

 the third early in September ; and sinee hiberating butterflies continue on 

 the wing- late in the spring, the imago may be found at almost every season. 



The butterflies have an active flight, and are found by roadsides and in 

 gardens, fields and sunny open spots in wooded districts. The caterpillars 

 subsist on nettles, and are rapid growers ; the chrysalis state averages 

 from ten to fourteen days in duration. 



The eggs are laid in clusters upon the under surface of leaves, usually 

 near the top of the plant, and are cylindrical in shape, scarcely taller than 

 broad, and furnished with eight to ten prominent, compressed ribs. The 

 young caterpillar closely resembles that of Euvanessa, but has somewhat 

 shorter hairs with a slight difference in their arrangement. The head 

 of the mature caterpillar is regular, and covered with bristly hairs, starting 

 from short tubercles, and the body bears on either side two rows of long, 

 tapering, thorny spines, and also, behind the first abdominal segment, a 

 dorsal series of similar appendages. During early life — the first two 

 or three stages — the caterpillars are sociable, living together under a 

 conniion web ; subsequently they disperse indiscriminately over the plant. 

 The chrysalids are very similar in general appearance to those of Euvanessa, 

 but all the protuberances, especially the dorsal projection of the meso- 

 thorax, are much less prominent. They hang a variable length of time, 

 from four to eighteen days, those of the European apparently longer than 

 those of the American species. 



By way of comparison with the habits of our own species, I may here 

 give a brief account of my observations on the European urticae. The eggs 

 are laid in rude clusters on the under side of leaves of nettles, about the 

 middle of the leaf, the uppermost leaves being usually selected ; but I found 

 one patch on a leaf about halfway up the stalk, and the little caterpillars 

 (all of which had not then hatched) had fonned a nest at the base of the 

 leaf. When very young, and apparently until their second moult, these 

 caterpillars live within nests formed by clustering the terminal half-opened 

 leaves of the nettle into a globular mass, liberally covered with web ; 

 after that the colony divides, some going in one direction some in an- 

 other, but keeping company in flocks, which w^ander from the summit of 

 one plant to a neighboring one, and leave the marks of their progress in 

 the blanched films of the upper leaves, all besmeared with web ; they seem 

 to prefer the upper leaves of a plant, and thus they sometimes swarm over 

 the whole surface of an extensive bed of nettles in full view, huddling in 

 clusters of individuals, Avhich are constantly creeping and recreeping over 

 each other ; when they wish to moult they seek, sometimes singly, some- 

 times in companies of as many as three or four, leaves growing lower on 

 the stem, or which at any rate have been but little, or not at all eaten, 

 and fold the leaf together much after the manner of V. atalanta ; the 



