4 GEOGRAPHICAL DISTRIBUTION 



localities, and have therefore nothing to do with the geographical distri- 

 bution of the Birds of any part of Western Europe — 



Phasianus torquatiis, 

 introduced from China^ a species ranging from Dauria to the Pacific, and 



Phasianus colchicus, 

 introduced from the basin of the Black Sea. 



Subspecies. 



After the exclusion of the doubtful species, and those which have been 

 introduced from distant countries, there still remain 391 species and sub- 

 species of birds which have a fair claim to be regarded as British ; but of 

 these there are thirteen subspecies which appear to be local races or 

 climatic forms of species which are already included in the British list, so 

 that the number of species of British Birds is reduced to 378. These 

 subspecies are : — 



Cinclus aquaticus melanog aster. 



Parus ater britannicus. 



Troglodytes parvulus hirtensis. 



Corvus corone comix. 



Loxia curvirosira pityopsittacus. 



Loxia leucoptera bifasc'iata. 



Fringilla linaria riifescens. 



Fringilla linaria hornemanni. 



Surnia fimerea hudsonia. 



Falco gyrfalco islandus. 



Falco gyrfalco candicans. 



Charadrius fulvus americanus. 



Charadrius hiaticula major. 



Inasmuch, however, as all these subspecies have gcograpliical ranges 

 differing from those of the typical forms (otherwise they could not claim 

 even subspecific rank) they must be regarded as sufficiently distinct to be 

 separately mentioned. 



Geographical Distribution of Birds within the British Islands. 



The Geographical Distribution of British Birds may be studied from 

 various points of view, and I propose in the first place to classify the 

 391 birds which have the greatest claim to be regarded as British accord- 

 in"- to the variation of their distribution within the British Islands. 



Those species which are found in the British Islands both in winter and 



