MIMICRY IN CEYLON BUTTERFLIES. 293 
transparent. Between the transparent and the dark part is a narrow 
opaque white area. During its fluttering flight the outer transparent 
portion of the wings is invisible, and even at close quarters this little 
dragon fly looks very like a butterfly. I subsequently met the insect 
again at Pannipitiya near Colombo, and my friends Dr. Willey and 
Mr. Dobell, who happened to be with me at the time, were both 
struck by its Lepidopteran appearance. I am doubtful whether to 
invoke Pseudaposematism or Pseudepisematism for the interpretation 
of this case. 
Another dragon fly which is interesting in this connection is 
Neurothemis tullia (Pl. I1., fig. 15). The general yellow-brown and 
black colouration of this insect, coupled with its peculiar sharp and 
jerky yet soft flight, so unlike that of most of its relatives, results in a 
distinct resemblance to the butterfly Rahinda hordonia (PI. IT., fig. 14) 
when on the wing. There may perhaps be some who would be 
tempted to argue that the dragon fly has developed its peculiar colour 
and flight in adaptation for deceiving and preying upon the butterfly. 
For their sake it may be pointed out that the dragon fly hawks insects 
in the bright sun, and I never met it in the shady localities frequented 
by R. hordonia. Whenever I saw it, moreover, it was in company 
with many dragon flies of larger and more powerful species, among 
whom it could hardly be regarded as judicious to masquerade in 
Lepidopteran guise. At the same time I may add that, though I 
frequently watched these groups of dragon flies, and though butter- 
flies of the genera Catopsilia, Appias, and Junonia abounded here, 
I never saw a dragon fly attack any of them. 
Lastly, I would draw attention to a small Chalcosid moth, Chalcosta 
venosa (P1. II., fig. 12), which was abundant along Lady Horton’s 
Drive during August. It has a remarkably Pierid-like appearance.* 
There is, however, no Pierid here with which it could possibly be 
confounded. 
EXPLANATION OF PLATES. 
Note.—With the exception of figures 7, 8, and 9 on Plate I. all the 
figures were made directly from the actual specimens by the four-colour 
process. 
Puate I. 
Fig. 1.—Male of Papilio polytes. 
Fig. 2.—Female (male form) of P. polytes. 
Fig. 3.—Female (aristolochize form) of P. polyies. 
Fig. 4.—Female (hector form) of P. polytes. 
Fig. 5.—Male of Papilio aristclochie. Tn this species the colouration 
of the two sexes is similar. 


a The white of the wings of this moth is, however, not due to the presence of 
uric acid derivatives, as in the Pieride. For this fact I am indebted to Dr. F. 
Vigan Ms very kindly made the requisite test (c/. Hopkins, Phil. Trans., 
95;ip: 
