on the Bionomics of Southern Nigerian Insects, 405 
forms have the queer habit of settling in great numbers on 
white-washed culverts, white stones and such things, where 
they are most prominent. [See Swynnerton in Proc. Ent. 
Soc., 1921, p. Ixiti, for evidence that Libythea seeks some 
chemical substance. | 
(Mr. Lamborn agrees with me that there can be no 
doubt that ‘‘ southward” and “ northward” were acci- 
dentally transposed in the above letter. As the passage 
stands it is inconsistent with the letter of March 20, 1915, 
and also with the following, written by Farquharson 
Aug. 23, 1918, to Dr. A. W. Hill, F.R.S., and published in 
Roy. Bot. Gard. Kew, Bull. No. 10, 1918, pp. 355, 356. | 
‘Harly in the rains for two or three days thousands of 
migrating Libytheine butterflies pass here flying southwards. 
The negro peasant knows that after that he may safely 
sow his cereal crops—maize, at any rate. Towards the 
end of the rains swarms of the same butterflies return north- 
wards. One may conclude that the rains are over. 
Between the flights to and from the forest belt we never 
see them.” 
D. A Lycarntp FALSE-HEAD-LIKE APPEARANCE 
PRODUCED BY TWO PIERINES IN COITU. 
[The attitude described was roughly illustrated in the 
following letter, but it is somewhat difficult to under- 
stand. In order that the antennae of the butterfly 
enclosed between the wings of the other should alone be 
visible it is necessary to assume that the abdomens are 
sharply bent into an §.] 
Aug. 11, 1918.—I read with special interest that theory 
about the false “ head” of Lycaenid butterflies. I hope 
you will not imagine that I was wise after the event, but 
the theory brought to my mind a curious error into which 
I fell a day or two earlier. On a plant in my garden I saw 
what I thought was rather a large white Lycaenid that I'd 
never seen before. With the exception of things like 
Catochrysops, few Lycaenids come up to the clearings round 
our quarters, most of them preferring the bush near the 
river. I was quite surprised at such a fine large one with 
rather long tails. Having no net I put out my hand to 
grasp it, but “it” flew away. “It” was really two 
moderate-sized Pierines in coit#, which had settled down 
on the plant. I wish I could draw their position, but you 
