( cxviii ) 



explanatidii wliicli takes cognisance only of the Sesiinae and (lioerocampinae. 

 The only ]ilansil)le explanation is, we think, the following : Sonth America was 

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

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

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

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

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

 was condguons witli tlie land nortli and east, and hence stood in connection 

 with North Europe, ])crhaps as India and Australia are connected by an Archi- 

 pelago. If we now assnme that the Sesiinae and the ancestral Xj/lophanea 

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

 America, while the AcheroiitiiiKie were essentially inhabitants of the Atlantic 

 Neotropical Archijielago or Island, or there represented by some generalised 

 genera, like the early I'l-otopia-ce, Amp/iimoea, and Cocytius, it is evident that 

 there was no barrier to j)revent 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 X>/lophanes and the 

 Sesiinae reaching the Atlantic and northern countries. 



The only northern Sesiine genus {Haemorrhagid) being a highly specialised 

 one, and the tropical Old World genera CepJionodes and Sutaspes being still 

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

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

 Atlantic Sphingid fauna of North America corroborates the evidence addnced 

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

 and Eastern Hemispheres. 



The Atlantic Nearctic Sphinyidae extend in Canada partly westward, and 

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

 Mountains and tlie jilatean west of them have no pronounced peculiarities in 

 the Sphingid fauna.- Tlie only distinctive features of tliis central district, which 

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

 not found outside the area (briicei) and the subspecies Haemorrkagia (///finis senta- 



The Palaearctic Region embraces Enrope, North Africa, Syria, Central 

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

 isinnds of Japan. It is inhabited by 75 si)ecies of Sphingidae, belonging to 

 33 genera : — 



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. 

 2 „ occur also in the Aethiopian Region. 

 1 „ are cosmopolitan. 



33 genera and TT) species. 



