Ixv 



acting as a model as well as mimic, Delias being well known 

 as a model for other Pierines, for Elymniines, Nymphalines 

 and Chalcosiine moths other than Psaphis. 



The facts now brought forward were quite new to Mr. 

 Prout and Dr. Dixey, and they were so extremely interesting 

 that it was to be hoped that the whole of the material collected 

 by Mr. Sanderson and Mr. Harvey would be available for 

 examination and the publication of a complete list, showing 

 the proportions of the various species. It was also of the 

 highest interest to repeat the observation, keeping separate 

 the evening and morning streams of migration so as to com- 

 pare the proportions of their constituents ; also to investigate 

 the areas reached by the two streams in order to determine 

 .the causes at work. 



The exact conditions under which the migrations took 

 place were of the highest interest and importance and it was 

 very fortunate that they had been accurately noted by the 

 captor, as would appear from the following letter, written 

 May 11, 1920, from the Research Laboratory, Petaling, F.M.S., 

 to Mr. W. A. Lamborn, who had seen the specimens in Mr. 

 Sanderson's collection and at once recognised the importance 

 of the discovery : — ■ 



" The following data relating to the butterflies and moths 

 you saw from Bukit Kutu may be of interest : — 



" Altitude of old Government Bungalow 3457 ft. 



" Period when insects taken 5th to 13th March, 1920. 



" The butterflies and moths were noticed by Mr. T. R. 

 Harvey and myself flying over the crest of the hill on which 

 the old bungalow stands, first time March 4, 1920, The 

 insects passed over from a deep valley about 5.30 p.m. to 6.45 

 p.m., sometimes two or three together at intervals of about 

 one to. two minutes and occasionally appearing in a more or 

 less continuous straggling line for ten to twenty minutes. 

 Generally a maximum number passed over in approximately 



large bright yellow spots on the fore-wings and brilliant red and yellow 

 markings on the hind. Another glaringly aposematic Oriental Chal- 

 cosiine, is the well-known Campylotes histrionicus, Westw. The pattern 

 of upper and under surface is similar in both these species, as it is 

 commonly in the whole subfamily. 



PROC. ENT. SOC. LOND., Ill, IV, V, 1920. E 



