222 BUTTERFLIES 



limited range in Canada and New England. It extends 

 south to Pennsylvania and Ohio and westward to Wis- 

 consin and Iowa. It is more abundant in northern than in 

 southern New England but it is often overlooked by col- 

 lectors who are not familiar with its haunts. It is es- 

 pecially likely to be found among the tall grass of swamps 

 and brooks running through lowlands. One of the best 

 ways to discover it is to beat the grasses in such situations. 

 The life-history of the Eyed Brown is fairly well known. 

 The eggs are laid chiefly on grasses and probably at times 

 upon the grass-like sedges. The larvae feed upon these 

 plants and become nearly full grown before winter sets 

 in. They then hibernate in this larval stage and the fol- 

 lowing spring complete their growth and change to chrysa- 

 lids in time for the butterflies to emerge in June. There 

 is but one brood a year. 



The White Mountain Butterfly 



Oeneis noma semidea 



To appreciate the extraordinary distribution of this 

 notable species one must let his fancy carry him back a 

 million years or so until he reaches that old time when the 

 whole northern part of the American continent was cov- 

 ered with an icy coating. Then he must follow the grad- 

 ual retreating of the ice northward, carrying with it won- 

 derful changes in climate and along with these climatic 

 changes taking northward many plants and animals 

 which were adapted to the cool temperature along the 

 borders of the glacier. As the ice cap retreated most of 

 these arctic forms retreated with it, and all along the 



