TET RAONIDE—PTARMIGAN. 227 
ROCK PTARMIGAN. 
Lagopus rupestris (Gme/.). 
Adult Male (Summer): Upper parts, chest and sides of 
body dark brown, barred and vermiculated with orange-brown, 
or cinnamon, darker on crown ; lores and tail-feathers blackish, 
the latter tipped with white ; vest of plumage white, the shafts of 
primaries blackish-brown ; bill, irides and claws dark brown : 
a comb over the eye light scarlet. Length rg inches; culmen 
0°6 ; wing 8; tail 4°75; tarsus 1°2. 
Adult Female (Summer): Above vermiculated, barred, 
or otherwise marked with pale cinnamon-brown and black ; 
inner wing-coverts similarly coloured to the back ; fore parts 
beneath dull ochre-yellow, barred and vermiculated with black ; 
lores not black ; some of flank-feathers ochreous, barred or ver- 
miculated with black; comb over the eye less conspicuous. 
Somewhat sinaller than the male. 
Aduit Male (Autumn): Upper parts with each feather 
vermiculated with brownish-grey and brownish-black, in about 
equal proportions, giving it a generally brownish-grey tint ; chin 
and upper throat chiefly white. 
Adult Female (Autumn): Above much as in summer, 
but feathers of hind neck are barred with creamy-white and 
black ; many of chin and upper throat-feathers white, neck and 
chest barred creamy-white and black ; rest of under parts white, 
excepting for a few cinnamon and black feathers on flanks and 
abdomen. 
Young (Autumn): Very nearly resemble their parents, 
according to the sex, but have the forehead chiefly white, and 
less indication of a comb over the eye; upper plumage largely 
mixed with white, much more so than adults at a correspond- 
ing date. 
Adult (Winter) : Indistinguishable from Z. mutus at same 
season. 
Distribution: Inhabits Iceland, Greenland, Arctic 
America, and possibly parts of Arctic Siberia. 
Habitat: Birch scrub in valleys, where there is plenty of bil- 
berry and Dryas octopetala, as wellas on rocky, mountain sides. 
Note,—The Spitzbergen Ptarmigan has been described under the name of 
L. hemileucurus, but as it chiefly differs from Z. rupestris in being a 
trifle larger, and in having more white on the bases of the tail- 
feathers, it seems doubtful whether it is worthy of specific rank. 
Q 2 
