( C'XXV ) 



AeUiiii|iiiui Hegioiis ; but, lieiiig almost excliisivi'ly tropiciil mid very lieteni- 

 morphic, bas tbo largest, uumbrr of Sphim/idac. The richest in Sphiiu/idae are 

 the western districts, India and the larger Sunda Islands ; farther cast there 

 is an obvious decrease in the nnmber of species atid genera, though Australia 

 possesses some genera of its own, and has, like the other Papuan countries, 

 many species which do not reach India. MarriKjInxsum remains abundant in 

 s]iccies almost everywhere except on the outlying isliind<. I'siloijramiiKi meiicphrnii, 

 and several species of Thfretra, lli/ijiotioii, and .]/(ic/-r)(//os.'i"w, are coniiunn I'riim 

 India to Quecn.sland and the iSnlomon Islands. The L'ol species which are 

 known belong to 64 genera. Tlie distribution is as follows : — 



36 genera and 226 sjiecies are Oriental. 



13 „ ,, 20 „ occur also in the I'alaearctio Hegion. 



6 ,, ,, 3 ,, ,, ,, ,, ,, and Aethiojiiaii Regions. 



6 „ ,, 1 „ ,, ,, ,, Aethiopian liegion. 



1 genus occurs in the Falaeavctic and Nearctic Regions. 



2 genera and 1 species are cosmopolitan. 



The proportion between i)urely Oriental and not purely Oriental genera and 

 species is : genera, 36 : 28 ; sjjecies, 226 : 21. The percentage of purely Oriental 

 genera appears to be small from these fignres, owing to the fact of all tlie 

 genera found also outside the Oriental Region being included in the 28, 

 though many of them are actually Oriental, especially those extending north- 

 ward into the Pacific 8ubregion of the Palaearctic Region, as detailed above. To 

 arrive at the correct figures, we have to sepa'^ate the indigenous genera, which 

 may have sent out some species beyond the limits of the Region, from the 

 genera of extraneous extraction. For the sake of simplicity we shall distinguish 

 only between tropical and northern temperate genera, leaving the discussion of 

 the relation of the Oriental fauna with the Aethiopian till we are dealing 

 with the latter. 



The mountainous districts of North India and China have biological 

 conditions favourable for species of the Palaearctic Zone. Vt'e find here several 

 northern Sphiiupdae and members of Palaearctic genera — for instance, Celerio 

 euphorhiiie and nicaea, Pcrgesa elpenor, llai'inorrliagia fiwifortnis, DoUiinopsis 

 ffriam, and Tkamnoecha uni/ormis. Phyllosphiniiia, Parum, and Dolhina reach 

 from Amurland or Japan to Assam or Sikhim. All the other genera common 

 to the Palaearctic and Oriental Regions are tropical ones, the proportion of 

 tropical to non-tropical genera of the Oriental Region being 58 : (i. 



Only 7 genera out of the 64 occurring are derivations from the American 

 stock {Apovali/jisia, I'xeuihilolhina, Cornotes, 'I'/inm/ioec/ni, J/afmorr/idflin, 

 CephonodcK, and Satas/ifis). The Australian genus Coeiwtes, of which only 

 one sj)ecies is known, is, likt; the North Indian genus Ajiorali/p.sin and its 

 derivative I'lfrndodolbinri, a zoogeograjjliical ]iuz/,le. Coow/cg is very close 

 if) Nfioyi'/ie from Argentina and Hra/.il, and Apoc(di/p»iis equally near 

 Euryglottin from tropical South America. The agreement between the 



