ARCTIC BUTTERFLIES CLARK 283 



males are very sluggish, and when they fly their flight is low, weak, 

 slow, and awkward. For the most part they remain more or less 

 hidden in the grass and do not fly until after they have mated and 

 some of their eggs have been laid. Their eggs are not attached to 

 the food plant, which is usually grass, but are simply dropped in 

 grassy places. 



The fact that the Erehias are grass feeders serves to restrict their 

 distribution as high Arctic butterflies in favor of others that are 

 less particular. 



A few of these butterflies are said to appear only in alternate years, 

 at least in certain districts, and others in alternate years are more and 

 less abundant. The reason for this is that these species require 2 

 years in which to reach maturity, and adverse conditions have re- 

 duced the numbers of one of the generations. 



The species of the related genus Oeneis are about 32 in number. 

 Some of them are found in the southern portion of the Arctic archi- 

 pelago north of North America, and in the extreme north of Europe 

 and of Asia. About one-half live only in North America, about six 

 are found both in North America and in the Old World, and about 

 a dozen occur only in Europe and in Asia — chiefly in Asia. 



Taken as a whole the species of the genus Genets (pi. 5, figs. 39-44) 

 have an enormous range. From southern Baffin Land they live west- 

 ward to Victoria Island north of Coronation Gulf and to the north- 

 ern portion of Alaska, and also from northeastern Siberia to the 

 North Cape. Southward they are found as far as Nova Scotia, 

 Bangor, and Mount Katahdin, INIaine, Mount Washington, New 

 Hampshire, Lake Superior and northern Michigan, North Dakota, 

 Montana, and northern California, and in the western mountains 

 southward to Arizona. In the Old World they range southward to 

 Kamchatka, Korea, Mongolia, Tibet, southern Russia, the Tyrol, and 

 Switzerland. 



But over this vast area thej^ are very irregularly distributed. Thus 

 in the eastern United States one species {O. jutta (pi. 5, figs. 39, 41) ) 

 is found only in a few bogs near Bangor, Maine, and in another bog- 

 in northern Michigan; another {0. katahdin (pi. 5, figs. 40, 42)) 

 is found only on Mount Katahdin; and a third {O. meJissa senvklea 

 (pi. 5, figs. 43, 44) ) lives only on Mount Washington in New 

 Hampshire and in its immediate vicinity. The first {O. jutta) 

 occurs in isolated and widely separated localities in Nova Scotia, 

 Quebec, Yukon, and Alaska, and similarly in the Old World 

 from eastern Siberia to Norway and southern Sweden. The second 

 {O. katahdin) is known only from Mount Katahdin. Forms closely 

 related to the third {O. melissa semidea) are found in Labrador, in 

 the region of Coronation Gulf, in Yukon, and in Colorado. As a 



