40 ME. G. T. BETHUNE-BAKEE : A REVISION OF THE 



reference to those forms in which I differ somewhat from the conclusions arrived at by 

 de Niceville regarding them. 



Coruscans (Wood-Mason and de Niceville) and pirama Moore. — These two forms are 

 the same ; I can trace no difference whatever in the colour of either males or females 

 from Ceylon and the Andaman Isles. 



6 . Upperside: both wings brilliant ultramarine-blue, sometimes'paler at the base, 

 but not always, with a very narrow black costa and outer margin. 



$ . Like the male in tone, but with the bases of the wings beautiful silvery greenish 

 metallic blue extending over nearly half the surface, with costa and outer margin in 

 the primaries very broadly black, increasing towards the apex ; in the secondaries the 

 costa is very broadly black and the outer margin by no means broad, but increasing in 

 width towards the anal angle. 



De Niceville (I.e.) says, referring to contscans: "The male may be known from 

 A. pirama on the upperside by its more brilliant and lighter blue coloration, and in 

 the female the brilliant basal blue portion is lighter and also better defined from the 

 darker deep blue portion beyond." This is perfectly correct as regards de Niceville's 

 specimens, which, through his great kindness, I have before me ; but it is not so at all 

 with those I have had from my friend Dr. Staudinger and others, the males being 

 precisely the same in every respect, and I have only one female to which it would 

 apply — all the others from Ceylon are absolutely the same in each particular as those 

 from the Andaman Isles. 



Pseudocentaurus Doubleday (amazona Pagenstecher). — This I take to be the Java 

 form of centaurus, of which I have a number of specimens before me : the blue of 

 some, not all, is rather brighter and bluer than ordinary centaurus Fabricius ; it is, 

 however, a curious fact that my only specimen, out of a great number, which is exactly 

 typical with the type specimen of centaurus in the Banksian collection is one from 

 Java, and is not of the dull purple of the common form, but rather brighter and bluer. 

 The blue of these Javan specimens is not nearly so bright as coruscans, but it is of 

 exactly the same shade as my Bornean specimens of centaurus Fab. and also as some 

 specimens I have from Singapore aud the west coast of Sumatra ; the under surface 

 is somewhat more variegated, but this is so very variable throughout all the forms 

 that no name can be based on it ; j^eudoccntaurus and amazona must therefore be 

 sunk under centaurus Fab. 



The species being a very common one is also very variable, and it appears to me to 

 serve no useful purpose to retain names for such a very slight variety as Doubleday's. 

 It is one of the most widely distributed species of the genus, but unfortunately it is 

 scarcely possible to state correctly the distribution of the type-form. Pirithous seems 

 t/> occur mainly in Sikkim and Assam and on the eastern side of India. Besides these 

 districts and Bhutan, I have it from Upper and Lower Burma; the type-form occurs 

 with it in both these latter localities. Coruscans Wood-Mason and de Niceville, as far 



