44 Allen's naturalist's library. 



webs white, and the outermost pair shows at least the basal two- 

 thirds of the outer web white ; on the median tail-feathers, 

 the amount of white decreases, being confined to the basal 

 third of the outer web in the seventh pair. 



Range. — Only known to occur in Spitsbergen. 



Ha'bits. — According to Mr. Abel Chapman, the cry of this 

 bird differs from that of the Common Ptarmigan and resembles 

 the " bee " of the Red and Willow Grouse, instead of the 

 hoarse croak of the Ptarmigan. 



VI. THE WHITE-TAILED PTARMIGAN. LAGOPUS LEUCURUS. 



Tetrao {Lagopus) leucurus, Swains, and Richards. Faun. Bor.- 



Amer. ii. p. 356, pi. 63 (1831). 

 Lagopus leucurus, Bend ire. Life Hist. N. Am. B. p. 83, pi. ii. 

 figs. 16, 17 (1892) ; Ogilvie-Grant, Cat. B. Brit. Mus. xxii. 

 p. 52 (1893). 



Adult Male and Female. — Distinguished from the allied species 

 at all seasons by having the outer tail-feathers pure while, as 

 well as by its smaller size. 



Male: Total length, 12-6 inches; wing, 7-3; tail, 4-3; tar- 

 sus, 1-2. 



Female: Total length, 12 inches ; wing, 7-2 ; tail, 37 ; t 

 sus, I "4. 



Range. — Only met with towards the summits of the Rocky 

 Mountains, from Alaska southwards to the north of New 

 Mexico. 



Changes of Plumage — Very similar to those of L. mutus and Z. 

 rupestris, but the black markings on the summer plumage of 

 the male are much bolder, and in winter the black mark in 

 front of the eye is absent. 



Habits. — The White-tailed Ptarmigan, Capt. Bendire tells us, 



is " a resident and breeds wherever found, rarely leaving the 



mountain summits, even during the severest winter weather, 



.and then only descending 2,000 or 3,000 feet at most, seldom 



