( 28 ) 



this section of Bornean Hesperidao. On one occasion, while 

 collecting on Mount Matang (near Knching), at an altitude of 

 2,000 ft., I watched this Hesperid flying slowly along the side 

 of the path in front of me, stopping every few yards and then 

 fluttering on again, and I was astonished to notice the re- 

 semblance in its flight to the moth, an example of which I had 

 captured on the path about ten minutes before. 



"The advantage of this pattern to the moth is at once 

 evident, for with its slow flight and a pattern resembling any of 

 the swiftly flying Hesperidae the advantage would be nil, but 

 given a slow flight and a pattern resembling a slow flying 

 Hesperid, then the advantage becomes very real. The instance 

 may be classed under the heading of pseudaposematic mimicry, 



[lxxv 

 since the moth is very probably palatable and the Hesperid 

 the reverse. 



" Two other Hesperids, occurring in Sarawak, bear the same 

 upperside pattern, viz. Keroma gemmifer, But)., and the larger 

 K. a/rmata, Druce. Both are fairly common species, occurring 

 in the same locality as Koruthaiolos xanites, and possibly 

 present a case of Bynaposematio mimicry, but I do not know 

 their flight, and so refrain from further comment. 



"2. M<>th (Sub-fam. Chalcosiinae) mimicking a butterfly 

 (Fam. Pieridcn ). I had for some time Buspected the 9 of the 

 Chalcosid moth Mimeuploea (Pidorus) inehtsus, Wlk., of being 

 a mimic of the common Pierine, Terias hecdbe, L., but it was not 

 till the capture of the ? of an interesting allied species Chahosia 

 (Cyclo8ia) hecabe, Jord., in .May last, that I felt at all positive 

 about it. The majority of Sarawak females of M. (/'.) inclustu, 

 which is common enough, have a black hind-margin to the 

 fore wing, the inner edge of which is moderately c\ en, and not 

 indented in that marked manner characteristic of the Pierine, 

 Terias Keoabe. Now tho ? of Chalcosia {Cydosia) hecabeh&e 

 this very indentation reproduced, and possessing also a 

 pale yellowish ground-colour, is an excellent mimic of the 

 Pierine.* M. (/'.) inclusics, on the other hand, exhibits only 



* Both these $ 9> together with their *, r, , which are entirely 

 unlike Terias hecabe, are figured in 5 bmett., x, pi. :'>, d 



| 1907).— E. B. P. 



