EURASIAN & AUSTRALIAN NEPTINI 7 



ORIGIN AND DISTRIBUTION OF NEPTINI 



The Neptini are closely related to the Limenitini and should not, in my opinion, 

 be placed in a separate subfamily, as has been done by some modern authors. The 

 tribe is at present widespread in the Ethiopian Region and in the Oriental Region 

 (sens, lat.), with slight extensions into the Palaearctic and Australian Regions. 

 There can be no certainty as to the origin of the tribe but, based on present dis- 

 tribution, it seems probable that the original birthplace was in Eurasia at a time 

 when the climate was milder ; subsequently deteriorating climatic conditions 

 would have forced the bulk of the tribe southwards into the Indo-Malayan and 

 African tropics, leaving in more northerly areas only those species able to adapt to 

 more rigorous conditions. 



The African species are superficially very different from the Oriental species, 

 but on grounds of male genitalia alone the species included in Neptis by Eltringham 

 seem to fall broadly within that genus, though without close relationship to any of 

 the existing Oriental groups. 



Within the Oriental Region (sens, lat.) there seem to have been three main centres 

 of development and distribution, which I designate the Sino-Himalayan, the South 

 East Asian and the Papuan. The first of these centres includes the basin of the 

 Yangtse-Kiang and the mountains which connect it to the Himalayas and to the 

 highlands of Vietnam, Siam and Burma. This area has been treated by some 

 authors as Palaearctic, but I regard it as a primarily Oriental area in which numerous 

 Palaearctic elements are intermixed through invasion from the North and eastwards 

 along the high mountains of Central Asia. The Sino-Himalayan Neptini mostly 

 occur at low to moderate elevations, and seem to be closely related to the S.E. 

 Asian elements. 



The S.E. Asian area comprises the whole of what is normally regarded as the 

 Oriental Region, i.e. from India and S.E. China through the Malay Archipelago as 

 far as Weber's Line. I have subdivided it into three sub-areas, the Indo-Malayan, 

 the Philippine and the Celebesian, since many forms occurring in the two latter 

 sub-areas are sufficiently distinct to warrant specific status, and in some cases it is 

 not clear with which Indo-Malayan species they share a common descent. One or 

 two species with a restricted distribution in India and Burma may possibly have 

 originated in Peninsular India, but most of the species seem to be Malaysian in 

 origin. 



The Papuan area (including N.E. Australia — an area of recent colonization) 

 used to be regarded as a subregion of the Australian Region but, as pointed out 

 by Evans (1949 : x) the Papuan butterflies have far more in common with the 

 Oriental butterflies than with the true Australian butterflies. 



In Tables A and B I list the species according to their presumed centres of develop- 

 ment and distribution. Species which seem to be derived from a common ancestor 

 in recent times are placed on the same line. ' Species ' which may be no more 

 than subspecies of one another are linked by a hyphen. Duplex species (see 

 Toxopeus, 1930) are bracketed. Species which are derived from comparatively 

 recent invaders from other areas are indicated by an arrow before the species name, 



