EURASIAN & AUSTRALIAN NEPTINI n 



It will be seen that both Pantoporia and Phaedyma are distributed throughout 

 all three sub-regions. This suggests that they diverged from the common Neptine 

 stock at an early date and provides a further reason for giving them generic status. 

 It is curious that Lasippa, which because of its similar genitalia must share a common 

 ancestor with Pantoporia, yet because of its normal Neptine venation appears to 

 be closer to the archaic stock, should have a more restricted distribution. Possibly 

 its distribution was once wider. 



GEOGRAPHICAL VARIATION AND POLYMORPHISM 



Sino-Himalayan species 



Subspecific boundaries are not easily drawn on the Asiatic mainland. Forms 

 occurring in Western China usually differ a little from Eastern Chinese forms, 

 which are closer to the forms occurring in Siberia and Japan. Fairly well-marked 

 subspecies occur in an area from the Eastern Himalayas through the highlands of 

 Burma, Siam and Vietnam, and similar forms may extend down the mountains 

 into Malaya and, in one case (Neptis sankara), even into Sumatra. These forms 

 presumably merge into the Chinese forms in South China, but lack of available 

 material makes it difficult in most cases to see exactly how and where the change 

 takes place. Forms from the Western Himalayas differ from Eastern Himalayan 

 forms by having wider markings and a paler underside ground colour ; these 

 differences seem to be mainly, perhaps even wholly, due to lower average humidity. 

 Eastern and Western Himalayan forms are presumably joined by a cline in the 

 550 mile stretch of the Nepal Himalaya, but again paucity of material leaves the 

 location and steepness of the cline in doubt. Forms from the Upper Mekong 

 Valley (N.W. Yunnan), magnificently represented in the Oberthur collection, 

 usually differ quite markedly both from the Western Chinese and Eastern Himalayan 

 subspecies. The Upper Mekong Valley comprises a deep narrow trough between 

 very high mountains, and must be isolated from the geographically close and similar 

 troughs formed by the Upper Yangtse and Salween. It would be interesting to 

 know if these valleys also produce distinct subspecies, but unfortunately the British 

 Museum (Natural History) is without material from them. Formosa is mainly 

 populated with Sino-Himalayan species in very distinct subspecies. One species 

 (Neptis soma Moore) has unexpectedly reached the mountains of South India, 

 a feat which it shares with Colias erate (Esper). 



A curious phenomenon is that many species which have yellow or orange markings 

 in China change to white in Burma or in the Himalayas. The precise boundary 

 between yellow and white forms occurs in different places in different species, 

 suggesting that there is no single common cause for the change. All the yellow 

 species which occur in Formosa are white or whitish there, even in the case of the 

 Neptis ananta complex which maintains a yellow colour throughout the mainland. 

 Most of the yellow species produce in their yellow areas of distribution, occasional 

 varieties exhibiting varying degrees of albescence, but these are not true dimorphs. 

 Dimorphism does, however, occur in China in N. sankara antonia, which has a yellow 

 dimorph f. antonia Oberthur and a white dimorph f. sinica Moore, with only very 



