( ci.x ) 



each is so very small, that iieitbcr the Papuan nor the Pahicarctic countries can 

 he considered to be a Region in the distribution of the Sphimftdn \ But if we 

 sink theni both to the rank of a Hubregion of the Oriental Region, with wliich 

 the Palaearctic countries iiave 18 genera and Papuasia 19 in common, the most 

 characteristic feature of the terai)erate Old World would be swallowed up ; the 

 Oriental Region would receive foreign elements, and hence the relation of the 

 faunae of the Old and New Worlds Ije very much obscured. The Palaearctic 

 countries being jiarliciilarly important as a connecting-link between ihe Okl and 

 New Worlds, having many affinities with North America, as we shall see further 

 on, we give them the raidc of a Region, in spite of the close relationship with 

 the Oriental fauna. Here again we see that the purely numerical consideration 

 of a fauna does not give its true position in respect to geographical distribution. 

 In order to understand the composition of the fauna of a district, the 

 geographical origin of the various members has to be inquired into. A point 

 essential towanls this object is manifestly the knowledge of the relationship of 

 the various species. And as the grouping together of species into genera is 

 meant to be a gronjiing of species of the same origin, it is further evident that 

 the correct composition of the genera and their correct position in the classitication 

 are necessary premisses for sound zoogeograi)liical researcb. Exponents of zoo- 

 geograj)hy who rely on catalogues — in which the distribution is far more erratic 

 than in Nature — having themselves not enough knowledge of the animals to 

 detect mistakes, cannot go beyond the numerical stage in the treatment of the 

 distribution, and, if they do, will as often be wrong as right in their conclu- 

 sions, constantly finding in the faunae discrepancies and similarities which are 

 nothing but the result of an insufficient study of the animals in question. If 

 we took, for instance, the classitication of the Spliingiilae in Kirby's Cataloyue, 

 Butler's Revision, Druce's Heterocera nf Central America (in Biol. Centr. Amer.), 

 and Hampson's Mot/is of' India as the basis for the exposition of the geographical 

 distribution of these insects, we should find a far greater similarity between 

 the Neotropical Region and the tro[ii('s of the Old World than there really 

 exists, numerous genera being said to occur in both the Eastern and Western 

 Hemispheres, while closer inspection proves these genera to be quite " unnatural " 

 (heterogeneous), and the various heterogeneous components to belong to different 

 genera peculiar either to the New or to the Old World, Protoparce, " Diludia,'^ 

 " Trij>tO(/on" " Amhidi/x" I'xeHdosphinx, Darapsa, Pcrgesa, Macroglossiim, 

 " .\i'Ui>jius" ^^ ('lioeroca:m))ri" Tlicrctra, et('., etc., being names employed 

 erroneously for mixtures of Old and New W'orld Siihinijidai'. 



Proceeding to (examine more closely the couaposition of Ihe .Sjihingid fauna 

 of the various Regions, we take them in the order as they come in the tables of 

 distribution on p[). cv. and cvii. The Neotropical Begion is inh ibitedby 33 genera, 

 containing 237 sjiccics. Two of the genera {('idario and llcrxe) and one species 

 {(Jelerio lineata) are cosmopolitan. The remaining 37 genera may be classed 

 in two groups : 22 which are confined to the Neotropical Region, and 14 which 

 occur also outside it. We will examine the latter first. Tliey are : Protoparce, 



