THE SWALLOWTAILS 65 



the locality and the temperature. It commonly extends 

 over a period of four or five weeks. 



The Blue Swallowtail 



Laertias philenor 



The Blue Swallowtail is said to have closer affinity with 

 the splendid butterflies of the tropics than most of our 

 other Papilios. The sheen of metallic color upon its wings 

 is certainly suggestive of the broad expanse of similar color- 

 ings in the gorgeous butterflies from South America. This 

 species is easily recognized by the general blackness of the 

 front wings and the basal parts of the hind ones as seen 

 from above, about two thirds of the area of the latter being 

 overlaid with blue-green scales that give the metallic lustre 

 characteristic of the species. Near the outer border of the 

 basal half of the front wings there is a row of about five 

 rather indistinct whitish spots, this row being continued 

 more distinctly on the hind wings. On the under surface 

 the white spots of the front wings are more pronounced 

 than on the upper, while each hind wing is brilliantly 

 marked with about seven large orange spots, part of them 

 fringed on one or both sides with a distinct margin of white. 

 The extreme side borders of all four wings are distinctly 

 marked with white crescents and the fringes on the tails 

 as well as more or less of the darker fringes of the hind 

 wings are of a beautiful purple color. In the males each 

 hind wing has along the inner border a slender, pocket- 

 like depression which is said to be the seat of the scent 

 organs. (See plate, page 65.) 



This splendid butterfly is a southern species. It is 



