IN BUTTERFLIES 219 



This strikes us as the more remarkable since, in 

 the two New England genera which are most 

 closely allied to it, and with one of which it is usu- 

 ally directly associated, no such sexual distinction 

 is found. A somewhat similar example occurs in 

 the Black Swallow-tail (Papilio polyxenes), the 

 male of which presents upon the upper and under 

 surfaces of all the wings, a little distance beyond 

 the middle, a transverse series of yellowish or 

 orange spots, which are equally distinct on the 

 under surface of the female, but partially or some- 

 times wholly obsolete above. In the Whirlabout 

 (Thymelicus brettus) we have even a more conspic- 

 uous example. The female is very dark brown, 

 almost black, with two little yellow spots in the 

 middle of the front wings ; while the male differs 

 totally, being tawny, with indented brown borders 

 and an oblique black dash in the middle of the 

 front wings ; at first glance no one could suppose 

 them identical. In Semnopsyche diana the male 

 is a rich dark brown, with a very broad fulvous 

 margm upon all the wings, marked on the front 

 wings by one or two rows of black spots. The fe- 

 male, on the other hand, is a rich purple black, 

 with no trace of fulvous, but with the space where 

 it belongs occupied on the fore wings by three rows 



