TETRAONID^E. 60 i 



DESCRIPTION 

 Of a winter specimen, lat. 54°. 



Colour, snow-white to the base of the plumage ; quill shafts also white. Bill bluish or 

 greyish-black. Nails dark horn-colour, their edges pale. — Form. — Bill less compressed 

 than that of T. rupestris. Wings proportionally longer ; scarcely an inch shorter than 

 the tail : third and fourth quills longest. Tail very slightly rounded laterally ; of sixteen 

 feathers ; the middle pair incumbent on the others. Tarsi and toes thickly feathered. Nails 

 like those of T. saliceti. 



A specimen, evidently in the act of assuming its winter dress, has the base of the whole 

 upper plumage blackish-grey ; also a few straggling feathers on the breast and head, and the 

 bases of the tail coverts, partially clove-brown, cut by slender lines of yellowish-brown ; and 

 the quill shafts umber-brown towards their tips. — A spring specimen (lat. 54°) has the inner 

 webs of the second primaries sprinkled with clove-brown, the whole surface of the bird con- 

 tinuing white ; but on spreading aside the plumage of the head and back, a number of young 

 feathers are seen bursting from their sheaths, having blackish-brown webs, crossed by several 

 bars of deep ochre-yellow, very similar to the markings of T. rupestris. The feet of this 

 specimen are worn partially bare, and the toes are shortly pectinated near the nails, which 

 are also very short. 



A summer specimen (lat. 54°). Head and neck shortly barred with blackish-brown and 

 pale wood-brown or brownish-white ; the front of the neck paler. Dorsal plumage, tail 

 coverts, scapulars, tertiaries, and the posterior lesser coverts, blackish-brown, cut about half 

 way to the shafts by rather coarse ochraceous bars, intermixed with nearly an equal number 

 of feathers ochraceous throughout and thickly undulated with fine black lines. The breast, 

 belly, and flanks are mostly pale ochre, broadly blotched and barred with blackish- brown, 

 intermixed on the belly with some white feathers, and on the breast with a few of the finely 

 undulated ones. The vent, legs, tail (which is only partially grown), the outer border of the 

 wing, primaries, secondaries, and greater coverts, are white. The toes partially naked, not 

 pectinated : the nails short and much worn. 



A summer specimen, noted as young, has the dorsal plumage consisting mostly of the 

 ochraceous finely undulated feathers, fading on the head and neck to grey, and greatly 

 resembling the plumage of T. lagopus (of Scotland). The under plumage is duller and less 

 strongly barred, and there is less white on the wing than on the more mature specimen, — 

 the spurious wing, primary coverts, third and fourth greater quills, and two of the lesser ones 

 being clove-brown, with a slight mottling of yellowish-white. The white tail feathers are only 

 bursting from their sheaths, the long coverts being coloured like the back. Feet and claws 

 like those of the preceding specimen. The wing of this young bird is a quarter of an inch 

 shorter than that of the other four*. 



* I think it probable, from attentive consideration of the different specimens, that neither of the summer ones are 

 mature, and that the fine zig-zag markings will prove to be peculiar to the young ; if so, the full summer plumage of 

 the old bird will nearly resemble that of T. rupestris, except that the tail is white. — R. 



