THE CANADIAN ENTOMOLOGIST. 31 



bands, and like the females which laid the eggs. Therefore outside the 

 belt of dimorphism A lope produced Alope, but inside the belt Alope pro- 

 duced Ncphclc and Nephrfe produced Alope. 

 In conclusion : 



In Canada the typical Nephele is the only form representing the genus 

 Satyrus, except that possibly in some localities Alope or intergrades may 

 appear ; but if so, it is only occasionally. In New York and part of New 

 England a belt of latitude is passed where in one section or other both 

 these forms fly, besides an endless variety of intergrades. Finally, Alope 

 emerges in the south from this belt as the only form, and inhabits a broad 

 zone, which ends about with the southern line of North Carolina and of 

 Tennessee, but at the southwest flies in parts of Texas, and has become 

 slightly modified when compared with the Alope of the middle States. 

 And to the west, somewhere between New York and Illinois, Alope dis- 

 appears, and a slightly changed form of Ncphele presents itself, and occu- 

 pies the country to and on the eastern slopes of the Rocky Mountains. 

 In some cases this cannot be distinguished from the typical Nephele, but 

 as a whole, it has taken a departure, and has come to have differences in 

 its larva and chrysalis. I call this form variety Olympus (after the 

 companion of the satyr Marsyas when the latter had his little difficulty 

 with Apollo). 



The relationship between Alope and Nephele is in good degree paral- 

 leled by L. Arthemis and Proserpina, the first of which occupies the 

 northern half of the Continent, but is dimorphic with the other in a belt 

 of latitude which passes through the northern States from Maine to Wis- 

 consin. Proserpina emerges from this belt on the south, and grades 

 imperceptibly into Ursula, which last changes gradually till it has acquired 

 a type, in Arizona, as different from that in which it manifests itself in 

 Pennsylvania as the Texan Alope is from Alope of New York. This belt 

 is nearly coterminous on both north and south with the belt of dimorphism 

 in the Satyrids. It is worthy of note also that the dimorphism of P. 

 Turnus begins inside this belt. 



In this last-named species it has been supposed that the melanic 

 form (confined to the female, Glaucus) first originated by accident, and was 

 afterwards perpetuated and obtained an advantage over the yellow form, 

 and finally in good degree supplanted it throughout its southern area, and 

 that the existence of enemies had much to do with the suppression of 

 one form, while their absence favored the other. What influence has 



