THE WILLOW GROUSE AND PTARMIGAN. 43 



unless one knows the locality whence each individual is ob- 

 tained, it is practically impossible to name a specimen. Birds 

 from Iceland, Arctic America, Japan, and North Asia are indis- 

 tinguishable in summer and autumn, and those from Europe, 

 Scotland, and, apparently, also from Newfoundland and some of 

 the islands to the north of Arctic America are equally so, while 

 examples from Greenland have the markings somewhat finer 

 than in North American birds, though, like them, they be- 

 long to the more rufous form. In the white winter plumage, 

 all the forms are, of course, perfectly similar to one another. 

 The reader must judge for himself which view of the matter 

 is the most natural. He can regard the Ptarmigan and 

 Rock Ptarmigan as forming one widely distributed species 

 w^ith various climatic phases of grey or rufous plumage, which 

 occur in scattered localities ; or he may consider each local 

 form as representing an incipient sub-species or race, but, 

 from all we at present know, the former view seems prefer- 

 able. The mere fact that indistinguishable grey or rufous 

 forms are found in intermediate localities over a very wide 

 range, seems to show that only one polymorphic species really 

 exists. Among many parallel instances we may mention the 

 little Hemipode (Ttirfiix taigoor) found in India and the Indo- 

 Chinese countries, 



V. THE SPITSBERGEN PTARMIGAN. LAGOPUS HYPERBOREUS. 



Lagopiis alpt?ta, var. hyperborea, Sundev. in Gaim. Voy. Scan- 

 din. Atl. livr. xxxviii. pi. (1838). 



Lagopus hemileucuriis^ Gould, P. Z. S. 1858, p. 354 ; Dresser, 

 B. Europe, v. p. 179, pi. 482 (187 1). 



Lagopus hyperboreus^ Ogilvie-Grant, Cat. B. Brit. Mus. xxii. p. 



51 (1893)- 

 Adult Male and Female. — This species may be easily distin- 

 guished, at all seasons of the year, from the other Ptarmi- 

 gan, by having much more white on the basal part of the tail- 

 feathers. The second pair has the basal two-thirds of both 



