92 The Field Naturalist's Quarterly May 



from Brigue, much affected by bug-hunters of all nation- 

 alities in July for the beautiful blue Lyccsna zephyrus. 



In this species, represented on the Simplon and in the 

 Zermatt valley alone in Central Europe by the variety 

 lycidas, we have a remarkable instance of what is called 

 interrupted distribution. L. zephyrus is a southern species 

 haunting Russia, Greece, and the Balkan peninsula, and 

 it does not occur farther west. Yet, for some unknown 

 reason, it flourishes in this isolated spot, perhaps the sur- 

 vival of the fittest in a species once common to the Con- 

 tinent. We have a somewhat analogous case with one 

 of our least known Blues, a variety of L. cegon, the Silver- 

 studded Blue. The type is common both at home and 

 abroad, but a variety with dingy under - side and much 

 exaggerated ocellation had been named var. Corsica, as 

 peculiar to that island. A few years ago, however, the 

 identical variety was found to occur in Westmoreland, 

 and the fact is all the more remarkable as there seems 

 to be little in common either in climate or conditions 

 between the rainy county of Northern England and the 

 bright island set in the eternal blue of the Mediterranean. 

 Two other European species at least are separated in this 

 same incomprehensible manner — a lovely Spanish spring 

 butterfly, Zegris eupheme, rather larger and not altogether 

 unlike a Bath White with orange tips to the wings ; and 

 Satyrus hippolyte, of the same family as our Grayling, both 

 of which have not hitherto been observed between South 

 Spain and some districts of Russia. 



Alpine insects dearly love moisture. From very few Swiss 

 mountain roads and paths is water altogether absent, and 

 where the runnels have dried up or the rivulet receded, leav- 

 ing a little sand or mud exposed to the sunshine, there the 

 Blues and the Skippers especially love to congregate. I have 

 seen a patch of warm black earth in the Basses Alpes, where 

 water is scarcer and the torrents soon dried in summer, a 

 moving mass of azure and brown, the iridescent wings gleam- 

 ing in the sunlight like so many points of fire ; and both the 

 higher and the lower Alps are particularly rich in that family, 

 which has ever been a first favourite with collectors. In 

 England we have several beautiful species, notably the 



