350 W. HOVANITZ 



narrow range from only 10° to 20° N. Lat. It is absent from South 

 America. 



The Nymphalinae comprise the major part of the family Nympha- 

 lidae, and are not easily subdivided into further parts. The family 

 Pieridae can be divided into several large natural subfamilies. On 

 the other hand, the Nymphalidae can be subdivided only by remov- 

 ing a few odd forms since no large natural cleavage lines are ap- 

 parent. In fact, even the line between the Nymphalinae and the 

 Heliconiinae is poorly defined. 



The genera of the Nymphalinae do not fall into definite classes 

 such as tropical and northern. Instead, each seems to have its 

 specific range of temperature tolerance. One may be wholly tropical, 

 another subtropical, and another cold adapted. 



Euptoieta is tropically adapted but exists north and south to 3>S°, 

 and to 3,000 meters in the central equatorial region. Probably all 

 temperatures short of freezing are satisfactory, as colonies are quite 

 common at 3,000 meters in the Tierra Fria of the equatorial belt. 



Argynnis, on the other hand, is a cold-adapted genus. It exists to 

 82° N. Lat. and to 55° S. Lat., but it is absent in the equatorial 

 regions between 25° N. Lat. and 15° S. Lat., even at the higher 

 elevations. As is typical of northern types, the elevations at which it 

 survives are higher southward in the northern hemisphere and higher 

 northward in the southern hemisphere. Argynnis is a large genus 

 that exists around the world. If is best considered subdivided into 

 various subgenera. If this were done for the /\merican forms, at 

 least four subgenera would be recognized for North America and a 

 fifth for South America. Two of the groups that would be treated as 

 subgenera in North America extend nearly to the Bering Straits 

 and are represented in Asia. Thus, there is recent gene continuity 

 between America and Asia. The third subgenus is separated by a 

 considerably greater distance and, at least during the quaternary, 

 has been completely severed from the nearest relatives in Asia. 

 There has developed in the North American temperate zone a par- 

 ticular type not represented elsewhere. Likewise, the South Ameri- 

 can subgenus has been isolated so long that its type is not represented 

 elsewhere in the world. 



The genus Melitaea occupies the temperate part of North America 

 (also Eurasia) and is not represented south of 20° N. Lat. Phyciodes, 

 on the other hand, covers somewhat the same territory in the north, 



