DISTRIBUTION OF BUTTERFLIES IN THE NEW WORLD 351 



but it occupies in addition the equatorial zone at 3,000 or 4,000 

 meters altitude to 20° S. Lat. and extends to 25°. 



The genus Chlosyne is equatorial and occupies the lower elevations 

 (less than 2,000 meters), with extensions to 35° N. Lat. and 25° 

 S. Lat. 



Microtia, Gnathotriche, and Morpheis occupy narrow zones in the 

 northern part of the equatorial region. Undoubtedly, revision of 

 these genera would prove desirable and would indicate relationships 

 better. 



Polygonia is a northern type that extends from 68° to 20° N. Lat. 

 and occurs at higher elevations in the south. Nymphalis {Vanessa) 

 is slightly less a northern type, extends less far to the north (to 

 50° N. Lat.), but farther to the south (to 10° N. Lat.). Vanessa 

 (Pyrameis) is also not such a northern type, having about the same 

 northern distribution as Nymphalis but extending over the tropics at 

 2,000-3,000 meters elevation and existing south of the equatorial 

 regions as well. Representatives of this genus exist throughout the 

 world in cold or temperate regions. Contact with Eurasia is broken 

 by a considerable distance across the Bering Straits, but probably 

 only a little increase of ocean temperatures would be sufficient to 

 connect them again. 



All the remaining genera of this subfamily are equatorial and 

 seem to owe their origin to America. A few, however, have been able 

 to survive colder temperatures and are found north or south of the 

 equatorial zones. Victorina extends to 30° N. Lat. and to 30° S. Lat. 

 Didonis extends to 30° S. Lat. Cystineura and Megalura ( = Timetes) 

 extend to 27° N. Lat. and to 25° S. Lat. Myscelia extends to 30 N. 

 Lat. and to 25° S. Lat. Historis and Pyrrhogyra extend to 25° S. Lat. 

 A few genera, for example Lucinia, Balboneura, and Peria, have very 

 restricted ranges. These suggest relict genera. Several genera extend 

 northward only to Panama (for example, Cybielis, Callithea, Haema- 

 tera, Panacea, Agris, and Zaretes). Others that extend north or south 

 of the equatorial zone by 5°-10° are Cybielis, Eunica, Callicore, 

 Dynamine, Cyclogramma, Adelpha, Ageronia, Chlorippe, Prepona, 

 and Anaea. Some of these extend only to the north; others only to 

 the south. 



Two of the genera having equatorial affinities, Limenitis ( =Basi- 

 larchia) and Asterocampa, are found only in the northern temperate 

 latitudes. Limenitis extends from 15° to 50° N. Lat. and Asterocampa 



