( cxviii ) 



cxjilaiiutidii wliicli takes cognisance only of the Sesiinae and Clioerocamjnnae. 

 Tlip only ])lansil)le explanation is, we think, the following : Sonth America was 

 at an early jicriod divided into an Atlantic and a Pacific Island (or Archipelago). 

 Tlie Atlantic Islands were in connection with what are now the West Indies, 

 and these were continuous with the Atlantic portion of North America, which 

 was likewise divided, by a broad sea corresponding to the Mississippi plains, 

 into an Atlantic and a Pacific Island (or Archipelago). This Atlantic country 

 was contiguous with the land north and east, and hence stood in connection 

 witli North Europe, perhaps as India and Australia are connected by an Archi- 

 jielago. If we now assume that the Sesiinae and the ancestral Xylopkanes 

 were almost entirely restricted to the Pacific Island of what is now South 

 America, while the Acherontiinae were essentially inhabitants of the Atlantic 

 Neotrojiical Archipelago or Island, or there represented by some generalised 

 genera, like the early Protoparce, Ampliimoea, and Cocytius, it is evident that 

 there was no barrier to prevent the Acherontiinae from entering the Atlantic 

 Nearctic Islands, and crossing over the northern countries to North Europe 

 and Asia, whereas there was little chance of the early Xi/lophanes and tlie 

 Sesiinae reaching the Atlantic and northern countries. 



The only northern Sesiine genus {Haemorz-hagia) being a highly specialised 

 one, and the tropical Old World genera GepkonoJes and Sataspes being still 

 more modified, speak for the distribution having taken place in the direction 

 indicated ; and the great percentage of elements of Old World descent in the 

 Atlantic Sphingid fauna of North America corroborates the evidence adduced 

 that there was a road of communication in the North between the Western 

 and Eastern Hemispheres. 



The Atlantic Nearctic Sphingidae extend in Canada partly westward, and 

 meet the western species in British Columbia and Washington. The Rocky 

 Mountains and tlie ]ilateau west of them have no i)ronounced peculiarities in 

 tlie Sphingid fauna. Tiie only distinctive features of this central district, which 

 ranks as a Subregion in other groups of animals, are a species of Haemorrhagia. 

 not found outside the area (hnieci) and the subspecies Haemorrhagia diffinis senta- 



The Falaearctic Kegion embraces Europe, North Africa, Syria, Central 

 Asia, Persia and Afghanistan, North China, Amurland, and the three main 

 islands of Japan. It is inhabited by 75 species of Sphingifhe, belonging to 

 33 genera: — 



7 genera and 52 species are peculiar to the Palaeartic Region, 

 occur also in the New World, 

 is found in the Nearctic and Oriental Regions, 

 occur also in the Oriental Region, 

 occur also in the Oriental and Aethiopian Regions, 

 occur also in the Aethiojiian Region, 

 are cosmopolitan. 



33 genera and 75 species. 



