14 



Turning now to the zoological region in which Japan is embraced, 

 it may be convenient to glance at the zoo-geographical realm defined 

 by Heilprin (" Distribution of Animals ") as the Holarctic, which 

 comprises the Palsearctic and Nearctic regions of Wallace and others, 

 but with certain modifications to which further reference will be 

 made. The southern limits of this realm, at least in the Eastern 

 Hemisphere, with which we are only concerned at present, are 

 formed from the Bay of Biscay to the Caspian by the Pyrenees, Alps, 

 Balkans, and Caucasus ; thence by the northern line of Persia and 

 Afghanistan, the Himalayas and the Nanling mountains in China. 

 This constitutes the Eurasiatic division or region, and is divided 

 into four sub-regions as follows : 



Boreal. — Includes the whole of Europe and Asia, north of an 

 imaginary line running from the Norwegian coast at about the 66th 

 parallel, and terminating on the East Asiatic coast at the 50th 

 parallel or thereabouts. The line of demarcation represents the 

 northern limit of cereals, and reindeer do not usually travel southwards 

 beyond it. 



European. — Defined northwards by the Boreal limits, southward 

 by the Alpine ranges, and eastward by the Caucasus and the 

 Caspian. 



Central Asian. — Lies between the European and Manchurian 

 sub-regions, and has its northern boundary limited by the Boreal line. 



Manchurian. — Includes Japan, Corea, Manchuria as far northas the 

 Amur, Northern China, with a westerly extension along the northern 

 face of the Himalayas. 



A considerable tract of the Pal^arctic region, as defined by 

 Wallace, is treated by Heilprin as a transition area, wherein occur 

 genera and species belonging to the Eurasiatic, to the Ethiopian, and 

 to the Oriental regions. This he styles the Mediterranean or Tyr- 

 rhenian region, and it embraces the peninsular portion of Southern 

 Europe, North Africa, Asia Minor, Persia, Afghanistan, Beloochistan, 

 and the northern half of Arabia. 



The composition of the fauna of the Manchurian sub-region, to 

 which, as already stated, Japan belongs, is in some respects compar- 

 able to that of the Mediterranean transition tract just referred to. It 

 comprises genera pertaining to the Oriental regions, as well as those 

 proper to the Holarctic, the latter predominating in the more northern 

 portions, whilst the former are in greatest force in the southern parts. 

 There are in addition a few genera which seem to be peculiar to the 

 area. 



Somewhere about one-third of the genera of macro-Lepidoptera 

 occurring in Japan are European, or generally referred to as such. 

 Rather over 1 60 are well-known British genera. Twenty-two species 

 of Rhopalocera are common to Britain and Japan, while four other 

 British species are represented in Japan by very near allies. Eight 

 Sphinges are identical, or almost identical, in the two countries, and 

 three others are replaced in Japan by closely allied species. Among the 



