ARCTIC BUTTERFLIES — CLARK 281 



swift. The females are met with, though very rarely, much lower 

 down, almost or quite at timber line (about 7,000 feet). 



Another kind {B. alherta), according to Edwards, flies on the steep 

 upper slopes of the mountains, the females generally higher up than 

 the males. The males spend most of their time racing restlessly up 

 and down the slopes, flying so close to the ground that they appear to 

 glide over the surface. Dr. Arthur Gibson says that this is less of 

 a peak lover than the preceding, much more local and less common, 

 but not nearly so difficult to capture. 



In one {B. pales) the small individuals that live in high alpine 

 regions rush along close to the ground with a direct and very fast 

 flight, with the wings moving rapidly and continuously. They are 

 fond of basking in the sun on warm stones with the wings spread 

 widely. But the larger lowland individuals differ in their habits 

 from the smaller alpine ones. 



In most of these little butterflies the females are less active than 

 the males, though the flight of the two sexes is very much the same. 

 In many the females are noticeably less adept on the wing than males, 

 and in a few (as in B. amathusia) the males have a rather rapid 

 flight, the females a considerably slower and more labored flight. 



Bogs, moorlands, damp meadows, wet woods, and mountain sides, 

 form the usual home of these little f ritillaries ; but some fly about 

 dry hillsides as well as in boggy places, one {B. epithore) lives in the 

 waterless mountains of Utah and Arizona as well as among more 

 congenial surroundings, and one {B. hegeriione) flies in the Kuruk- 

 tag — dry mountains — in the Gobi desert in East Turkestan, southeast 

 of Kurla. 



THE ARCTIC SATYRIDS 



Companions of the bog fritillaries throughout a large portion of 

 their range are those somber brownish butterflies of small or medium 

 size known as Erebias (pi. 3, figs. 29, 30). 



The Erebias as a whole range from the Arctic coast of North 

 America, including the southern portion of the Arctic archipelago, 

 southward to Hudson Bay, and in the west to the high mountain 

 peaks of New Mexico. In the Old World they live from Scotland, 

 northern England, and northern Norway eastward to northeastern 

 Siberia and southward to southern Europe, Armenia, Kurdistan, 

 northern Persia, Afghanistan, Kashmir, Tibet, Sikkim, and the 

 mountains of central Japan. Far removed from any of its relatives, 

 a single species is found in Patagonia. 



There are about 75 kinds of these somber little butterflies, and 

 many are very variable, so that about 200 forms have been described. 



