NOTES, : 179 
(1) In the beginning of January, 1907, when we were lying in 
Colombo harbour, several specimens of T’'ros (Papilio) hector, L., flew 
off to the ship one night. 
(2) On the evening of 17th January, 1907, we were anchored off 
Beruwala, quite a mile from the nearest land. About 9 P.M. a few 
individuals of Tros (Papilio) hector, L., suddenly came on board and 
were accompanied by numbers of Parnara cingala, Moore. It was 
a cloudy, sultry night, with a little rain ; there was no wind at the 
time, but later on a slight southerly breeze got up. 
The numbers of the butterflies—the P. cingala must have been 
in scores—combined with the distance from land prohibit the idea 
of any mere chance. Their flight must have had some definite 
object, and that, I believe, was migration. However, the evidence 
is slender, and this note is merely intended to call attention to the 
facts and to elicit corroboration. 
The only previous records of such nocturnal migration to which 
I find references, are in the cases of Hugonia j-album and Anosia 
archippus, as related by Scudder,* so that any evidence appears 
noteworthy. 
T. BAINBRIGGE FLETCHER. 
H. M. S. Sealark, 
February 15, 1907. 
7. Significance of the Stridulation in Manduca.—On 28th June, 
1906, I found a specimen of Manduca (Acherontia) styx, Westw. 
(the Asiatic Death’s-head moth), on a tree on Little Sober Island, 
Trincomalee. It was not on the trunk, but clinging to a slender 
twig, two or three inches away from the trunk, and about seven feet 
from the ground. This moth readily flew when disturbed, although 
the sun was shining very strongly (5 p.m.). It stridulated loudly 
when touched and when on the wing, and most of all when being 
seized in the net. 
A few days before I had netted a small leaf-nosed bat at dusk and 
had noticed that it squeaked loudly when caught. This sound was 
exceedingly similar to that of the Manduca, and I suggest that the 
cry of the latter mimics the squeak of a small bat. Bearing in mind 
the comparatively large and needle-sharp teeth of such a bat, I can 
quite imagine that this cry in the moth would have a pseudapose- 
matic effect on,an enemy, and on further irritation the effect is 


* Quoted by Tutt, *‘ Migration and Dispersal of Insects,”’ page 46. 
+ A detailed account of the cry of the imago of the Death’s-head moth will 
be found in the fourth volume of J. W. Tutt’s ‘‘ British Lepidoptera,” 1904, 
p. 444. A figure of the vocal mechanism by Moseley is quoted from ‘‘ Nature,”’ 
vol. VI., pp. 151-153. 
