( exxv ) 



Aethinjiian KeLrions ; but, lieiiig almost exclusively tn.pical ami very hetero- 

 morphic, has the largest iuimb.;'i' of Sphingidac. The richest in Sp/t/iH/idaL' are 

 the western districts, India and the larger Snnda Islands ; farther east there 

 is an obvions decrease in the number of species and genera, thongh Australia 

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

 many species which do not reach India. ^fac■rn<Jlossl(m remains abundant in 

 s))ecies almost everywhere except on the outlying islands. I'si/of/ramm't me/te/j/iro/i, 

 and several species of Thrrefra, Uippofioji, and Macroylossum, are common from 

 India to Queensland and tlie Sulomon Islands. The 251 species wliich are 

 known belong to 04 genera. The distribution is as follows : — 



3f3 genera and 226 species are Oriental. 



13 „ „ 2U „ occur also in the Pa.laearctic Uegion. 



6 „ ,, .3 „ „ „ ,, ,, and Aethiopian Regions. 



6 ,, ,, 1 ,, ,, ,, ,, Aethiopian Region. 



1 genus occurs in the Palaearctic and Xearctic Regions. 



2 genera and 1 species are cosmopolitan. 



The proportion between purely Oriental and not purely Oriental genera and 

 species is : genera, 36 : 28 ; sjiecies, 226 : 21. The percentage of pnrely Oriental 

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

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

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

 ward into the Pacific Subregion 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 trojiical and nortbern temperate genera, leaving the discussion of 

 the relation of the Oriental fauna with the Aethiojtian 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. AVe find here several 

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

 euphorhiae and nicaea, Pergesa elpenor, Harmorrhagia fuci/ormis, Dolbinopsis 

 f/n'sca, and Thamnoecha uniformis. PlnjUosphiiu/ia, Parum, and Bolbina reach 

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

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

 tro))ical to non-tropical genera of the Oriental Region being 58 : 6. 



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

 stock {Apocali/psis, Pseudorlolbina, Coenotes, Tliamnoecha, llaniiorrhaijifi, 

 CfiphoHodes, and Sataspes). The Australian genus Coettotcs, of wliich only 

 one sjjecies is known, is, like the North Indian genus Apocalgpsis and its 

 derivative PseudndolhiiKi, a zoogeographical puzzle. Coenotes is very close 

 to Neogene from Argentina and Brazil, and Apomlgpsis equally near 

 Eurgglottis from tropical South America. The agreement between the 



