1895.] L. de Mceville & Dr. L. Martin — Butterflies of Sumatra. 511 



574 Papilio (Menelaides) delianus, Fruhstorfer. 



P. doubledayi, Wallace, var. delianus, Fruhstorfer, Ent. Naoh., vol. xxi, p. 196 

 (1895). 



Hagen as doubledayi. Originally described from Deli in Sumatra. 

 Wallace gives P. coon, Fabricius, from Sumatra, Java, and Borneo, 

 and says that P. doubledayi, "Wallace, the Indian form, differs from it 

 in having the markings red instead of yellow. The Sumatran form 

 in both sexes has the markings at the anal angle of the hindwino- dis- 

 tinctly red, while P. coon from Java has them equally distinctly yellow. 

 The abdomen of our Sumatran examples is, however, more yellow than red. 

 We have thus true P. coon occurring in Sumatra, and also an interme- 

 diate form between that species and the continental P. doubledayi, shew- 

 ing the exact region where the one species is gradually becoming trans- 

 formed into the other. P. delianus is rare in the forests of the plains and 

 outer hills, is found at Selesseh, Namoe Oekor, and as high only as 

 Bekantschan. It chiefly frequents the flowers of high trees and so is 

 seldom caught. It has a fluttering but quick flight. Dr. Martin has 

 specimens from so far south as Asahan. Rothschild does not allow 

 P. delianus full specific rank, but records it is P. coon, Fabricius, {d) t 

 P. doubledayi delianus, Fruhstorfer. 



575. Papilio (Menelaides) neptunus, Guerin. 



Hagen as neptunus, var. sumatrana, Hagen. The Malayan Penin- 

 sula form of P. neptunus as figured by Distant has four crimson spots 

 on both sides of the hindwing in the male, while the Sumatran form 

 has only two ; the female has three spots on both sides in the Malayan 

 Peninsula form, while the Sumatran has two on the upperside and 

 three on the underside. In all other respects the species from these 

 two localities agree as far as I can see. I have not seen specimens from 

 Borneo, from whence P. neptunus is recorded by Wallace. It is certain- 

 ly one of the remarkable butterflies of the world ; the anal half of the 

 abdomen in both sexes being of a bright chrome-yellow colour is in 

 unique and startling contrast to the rest of the black abdomen and the 

 black wings with the crimson spots on the hindwing. No doubt this 

 staring yellow-tipped abdomen serves as a very efficient danger-signal 

 or warning-colour to the enemies of butterflies to leave this particular 

 species severely alone, the butterfly being obviously a protected one 

 and with a very strong scent. It is quite as rare as P. delianus 

 Fruhstorfer, and is found in the same localities. Its flight is very slow 

 and sailing, always high in the air and out of reach of the net. It is 

 almost impossible to obtain perfect specimens. Rothschild records this 

 species from Sumatra as P. neptunus, Gruerin, (a a ), ab. sumatranus 



