PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 227 



be recognized as a fairly definable race to be called Lagopus mutus 

 rupestris (Gm.) Ridgw.* 



The most striking variation of coloration is to be found in the ex- 

 amples from Greenland and Cumberland Gulf. If the summer plum- 

 age is to be taken as the consideration which shall constitute a species 

 or race in this genus, then the birds from Greenland and Cumberland 

 Gulf should be recognized as a definable form, for which the name Lago- 

 pus mutus rclnhanlti (Brehm) should be used, unless the Iceland bird 

 should prove to be identical (and this I have had no opportunity of 

 verifying), in which case the birds of all the localities named above 

 should then receive the name Lagopus mutus islandorum Fabeb. 



The birds procured by me at Atkha Islands (Aleutian chain) present 

 still greater variations of coloration, and appear to represent a well- 

 marked local race, for which I propose the name Lagopus mutus 

 atl'hensis. 



The following descriptions of summer specimens, together with the 

 table of comparative measurements, will help to establish tbe relation- 

 sliip of the four races recognized in this paper : 



1. Lagopus mutus (typims). 



No. 34120, Lapland (67° N.), <?, ad., July 3 7, 1855. 



Head and neck dusky, with light gray tips to many of the feathers, 

 and others having an obscure yellowish-brown spotting near, but ante- 

 rior, to the gray. The back, rump, tail-coverts, and scapulars very 

 dusky, much vermiculated with grayish and fulvous, the rump having 

 a tendency to zigzag, fine markings almost approaching bars on the 

 lower portion. Jugulum and breast having few light yellowish-brown 

 spots, especially on upper breast and sides of the neck. The sides and 

 flanks are strongly but sparsely barred with dusky and light bufi". Tail 

 entirely black. This example is identical in plumage with No. 33546, 

 ^, marked ''T. lagopus,^^ from Norway, summer; and with 43680, <?, 

 marked ''X. rupestris,''^ from the Barren Grounds of Arctic America, late 

 spring. 



No. 33547 <?, ad., labeled "i. alpinus,''^ Norway, July 0, 1802. 



Head black, feathers narrowly tipped with brownish-yellow; entire 

 neck black, the feathers tipped with pure gray; upper back black with 

 narrow bars of light fulvous; back and rump black with fine dots of 

 gray and fulvous, which latter disappear on the lower rump and upper 

 tail-coverts, where replaced with small gray dots, and each feather 

 tipped w ith a narrow crescentic band of grayish white. Jugulum and 

 sides black with fine dots of white and buff, inclined to spotting. The 

 tendency to produce bars is in this example nearly obsolete. The tail 

 with a rather broader tip of white than in other specimens. 



No. 34119, 2, ad., "i. alpinus,^^ Lapland, July, 1855, and No. 18897, 

 $, ad., "X. mutus,''^ France, late spring. 



*See "Hist. N. Am. Birds," vol. iii, pp. 456, 462. 



