216 



LEPIDOPTERA. 



for its growth and increase, it extended its habitat till, 

 in 1883, it had reached the Rocky Mountains, and by 

 this time it probably holds possession of the whole 

 United States.^ 



The family Papilionidae includes 

 the species Eucheira socialis, found 

 in Mexico. These butterflies live 

 together in large numbers in a parch- 



Fig. 170. 



Fig. 171. 



ment-like nest reminding one of the 



social Hymenoptera. 



Another species of the same 



family, Papilio ajax, illustrates in a 

 most remarkable manner the effects of temperature 

 upon structure. This species is distributed widely from 

 Southern Canada all through the Southern Atlantic 

 States to Florida, and the Gulf States westward in 

 Missouri. 



There are three distinct varieties of the species, 

 comprising in each variety both males and females, 

 originally described under the names of Walshii, Tela- 

 monides, and Marcellus. Walshii and Telamonides are 

 not found in the extreme northern range of the species, 

 where Marcellus alone survives. 



Starting in the springtime in West Virginia, we find 



1 See Scudder, " The Introduction and Spread of Pieris i-apce 

 in North America," 1860-1885, Mem. Bost. Soc. N'at. Hist., 

 Vol. IV., No. 3, 1887. 



