124 



ROCK PTARMIGAN. 



of which two are incumbent, less strong, and longer than the rest by two- 

 twelfths of an inch. 



Bill black; superciliary membrane scarlet; claws dusky, towards the end 

 yellowish. The plumage is pure white, with the exception of a broad band 

 of black from the upper mandible to the eye, and for a short space behind it; 

 the shafts of the six outer quills, which are brownish-black, and all the tail- 

 feathers, the two middle excepted, they being of a deep greyish-black colour, 

 with a terminal narrow band of white. 



Length to end of tail 13^ inches, to end of wings 12; wing from flexure 

 8; tail 4^; tarsus ly 2 ^; hind toe -f^, its claw yV, middle toe yf, its claw yV 



Male in summer. 



In summer, the plumage differs little in texture, with the exception of 

 that on the feet, which is short and thin on the tarsi, worn on the base of 

 the toes, of which the soles and half of the upper surface are denuded. The 

 bill and claws are of the same colour as in winter; but the plumage is 

 variegated with black, reddish-yellow, and white. The upper parts may be 

 described as black, transversely and irregularly banded and spotted with 

 yellowish-red, the feather terminally margined with white, there being on 

 each feather several bars of yellowish-red running from the margin inwards, 

 but leaving a black space in the centre. The lower parts are lighter, more 

 broadly and regularly barred with brownish-black and light reddish-yellow. 

 The feathers along the edge of the wing, the alula, primary coverts, nearly 

 all the secondary coverts, primaries and outer secondaries, white; as are the 

 lower surface of the wing, the axillar feathers, and some of the feathers on 

 the abdomen, as well as those on the feet, the latter being soiled or tinged 

 with yellowish or grey. The shafts of the primaries are brownish-black, and 

 the tail is black as in winter, tipped with white, and with the lateral feathers 

 having part of their outer web white; the two middle feathers barred like the 

 back. The dimensions of an individual are as follows: 



Length to end of tail 13^ inches, to end of wings 11^; wing from flexure 

 7 T f ; tail 4|; bill along the ridge y^; tarsus ly\; middle toe l^f, its claw '■£%. 



Female in summer. 



The female does not differ materially from the male, the yeilow bands 

 being only broader and lighter. 



Very great differences are observed in the length and form of the claws, 

 they being in some individuals very long, thin-edged, and tapering to a 

 rounded point; in others very short, being worn down to the stump. This 

 species is considerably smaller than the Ptarmigan of Scotland, which it 

 precisely resembles in its winter plumage. In its summer plumage, however, 

 it differs in having the markings larger; and as yet no specimens have been 



