56 THE BUTTERFLIES OF CEYLON 
external differences, but whose genitalia are very similar, 
and difficult to distinguish. Fruhstorfer says there are also 
two ‘colour forms” of nova, in Sumatra, whose genitalia 
are apparently identical. As in the atrata group, breeding 
seems to be the only solution. 
Tailed and tailless forms fly together all the year round, 
but the males are most often seen when the reads are wet. 
They both vary much in the markings on the under side, 
and specimens can be taken of both in which the basal strige 
fail to reach vein I. 
I have seen a few specimens in Galle, Colombo, Jaffna, 
Trincomalie, Anuradhapura, etc., but they seem commonest 
in the hills. Common at Ratnapura. . 
96. NACADUBA NOREIA. 
For some years past this name has been given to the tailless 
form of ardates, but Bingham points out that this does not 
at all agree with Felder’s description. It was originally 
described by him from a specimen taken at Nuwara Eliya 
on December 24th, 1864, and for the next fifty years it 
apparently escaped the notice of collectors. I have now 
managed to collect a good series. 
The five main distinctions are:—-1. The external margin 
is less convex, 2. The basal strigze on the under side of the 
fore wing do not extend below the median vein. 3. The males 
are a much brighter purple than ardates, and, in certain 
lights, have a broad purple-brown border. 4. The females 
have avery bright blue patch on both wings, as bright on 
the lower wings as on the upper; this I have never seen in 
avdates. 5. In both sexes the cilia at the apex of the 
fore wing are pure white, and on the hind wing they are paler 
than those of ardates. The fore wings are distinctly pointed, 
though not so much as in viola. The marginal spots on the 
lower wing of the female are obsolete, except in interspace 2, 
as Felder says ; and the under side agrees with his description 
in every particular. It seems to vary very. little. Mr. 
Riley exhibited a specimen at a meeting of the Entomolo- 
gical Society on-3rd March, 1920, and the following is an 
