A VARIABLE INSECT 



657 



it is subject. Of tlie series of specimens in the British ^ruseum, 

 all but one are coloured as follows : — 



The ground colour of the wings is black, the ba.sal portions 

 of both wings being gold-green glossed with blue, the colours 

 changing their relative positions in a strong light. In the 

 centre of each wing is a slightly-curved bar of rich crimson. 

 The body is of the same splendid colour as the base of the 

 wings, except that the abdomen is banded witli black. 



But there is one specimen which has the band across the 

 wings white instead of crimson. When I first saw this, I 

 naturally took it for a variety, but was informed by Mr. A. H. 

 Butler — who, like most of the officers of the Museum, is most 

 liberal of information to those who wish for it — that the speci- 

 men in question was really the typical- insect, and that either 

 the others must be varieties, or that they must be separated 

 into two distinct specie?. The difference of appearance is singu- 

 larly striking, the white-banded specimen having quite a plebeian 

 look among its companions, the blue and green of the base of 

 the wings not being set off by their complementary colour, whicli 

 enhances the brilliancy of both. 



The specific name glauca refers to the green colour which 

 has been mentioned. There are seven species of this genus in 

 the British Museum, and all are natives of South America. 



TJ U 



