450 Lieut.-Colonel N. Manders on the 
Brazil; and he suggests that possibly these green Papilios, 
or more probably their common ancestor, were thus intro- 
duced. He inclines to the view, however, that the citron 
is indigenous to all these islands. I should say that the 
Madagascar, Bourbon, and Mauritius green Papilios are 
probably derived from some African ancestor closely allied 
to P. nereus. 
Papilio phorbanta, L. (Pl. XXIX, figs. 6, 6a). 
Confined to Bourbon, where it is known as P. disparilis, 
Boisd. Common, not to say abundant, on the coast and 
up to about 2,000 feet. I never saw a single specimen at 
3,000 feet, and its distribution is no doubt determined by 
the food plant. It feeds on citron, and the larva has been 
figured and described by Vinson. It is no doubt un- 
palatable in the larval stage. The female is aberrant, 
and is an admirable example of what Scudder calls 
“colourational antigeny” in which it is the female that 
departs from the normal colouring of the group to which 
the species belongs. It is presumably a mimic of Huplea 
goudoti, and in such a small island as Réunion the exciting 
cause should not be difficult to discover. I may say fairly 
confidently, that there is no bird now existing which makes 
any marked ravages among the butterflies. Indeed birds 
are conspicuous by their absence, and are as rare in Réunion 
as they are in France and Italy, and for the same reason ; 
affording a marked contrast to Mauritius, where they are 
protected and consequently abundant. 
I was informed, however, by Dr. Jacob, who has resided 
for some fifty years in Réunion, that at one time the now ex- 
tinct “starling” (Pregilupus varius) was decidedly common, 
especially in those parts more particularly frequented by 
P. phorbanta, and, judging by the stuffed specimen in the 
St. Denys Museum, I should say that the bird was entirely 
insectivorous. I throw out the suggestion that it was this 
bird that was the main cause of this case of mimicry. 
We have therefore in these two islands two cases of the 
marked effect of birds on butterflies. In Mauritius, which 
had no indigenous starling, the introduction of the Indian 
siarling caused the extinction of Salamis auqustina, and 
in Réunion the presence of the Réunion starling gave rise 
to a remarkable case of mimicry. 
As habit, manner of flight and so forth is now regarded 
