456 NORTH AMERICAN BIRDS. 



spruce buds, tlieir flesh is said to be delicious; but after the snow shuts them 

 off from other food they feed on the fir buds, and then their flesh acquires 

 a strong flavor of turpentine. 



In the tree this Grouse is not an easy bird to discover ; so closely does its 

 plumage resemble the lichen-covered bark that it is difficult to distinguish 

 them, especially as, when alarmed, they crouch down lengthwise with the 

 limb, and thus become concealed. 



Genus LAGOPUS, Vieillot. 



Lagopus, Vieillot, Analyse, 1816. (Type, Tetrao lagopus, L.) 



Gen. Char. Nasal groove densely clothed witla feathers. Tail of sixteen or eighteen 

 feathers. Legs closely feathered to the claws. The northern species snow white in 

 winter. 



The Ptarmigans inhabit the northern regions of both hemispheres, and 

 with the Arctic fox and hares, the lemmings, and a few other species, charac- 

 terize the Arctic zone. They are of rare occurrence within the limits 

 of the United States, though farther north they become abundant. The 

 species all change to white in winter, except L. scoticus, which appears to be 

 merely a permanently dark, soutliern, insular form of L. albus. (See Alfred 

 Newton in Proceedings of the Philadelphia Academy, July, 1871, pp. 96, 97.) 



Species and Varieties. 



A. Tail-feathers always with more or less black. 



1. L. mutus. Bill small, slender, the length from the nasal groove to the tip 

 decidedly more»than the height through the base. Male in winter with a 

 black stripe on the lores. 



(J in summer with uniform black feathers on the breast; autumnal 

 plumage bluish-gray, mottled. Hob. Northern Europe . . -vax. mutus . 



$ in summer without uniform black feathers on the breast. Autumnal 

 plumage orange-rufous. Hah. Northern North America ; Greenland ; 

 Iceland var. rupestris. 



2. L. albus. Bill large, stout ; the length from the nasal groove less, or not 

 more, than the height through the base. Male in winter without black 

 stripe on lores. Hah. Northern Europe and northern North America. 



B. Tail-feathers entirely pure white. 



3. L. leucurus. Winter plumage wholly white. Hah. Alpine summits of 

 the Western mountain-ranges, from Colorado to Oregon and Washington, 

 and north into British America. 



