LAG OP US RUPESTRIS. 
349 
visitants. They are, however, found commonly on Newfoundland and in Labrador, migra¬ 
ting thence,' during winter, into Canada, reaching, perhaps, the New England States very 
rarely. The Willow Grouse, as they are sometimes called, inhabit the barren heaths and 
cold swamps of the countries of which I have spoken, and from these are distributed north¬ 
ward into the Arctic Zone. As mentioned, they are partly migratory during certain win¬ 
ters, being induced to come southward, probably, from lack of food, for this governs the 
migration of nearly all birds. 
LAGOPUS RUPESTRIS. 
Rock Ptarmigan. 
Lagopus rupestris Leach, Zool. Misc., II, 290. 
DESCRIPTION. 
Sp. Ch. Form, robust. Size, large. Tail and wings, long. Bill, rather slender, exceeding in length, measured from 
nostril to tip, the height at base. Sexes, quite similar. 
Coi.or. Adult in winter. White throughout, excepting tail which is black with the central feathers and tips of all 
white, and there is a black line from bill through eye. 
Adult in summer. Above, black, barred and spotted with yellowish-red; lighter below and broadly and regularly band¬ 
ed with yellowish-red; otherwise as in the male. Bill, black, iris, brown, claws, horn color, in all stages. 
OBSERVATIONS. 
Known from the closely allied albus by the black band through eye and more slender bill, this being longer than high 
at^base. Both species of Ptarmigans may be known from all other Grouse by the wholly feathered tarsus and feet. Dis¬ 
tributed in summer, throughout Arctic America, south, according to Audubon, about Bras d’Or. 
DIMENSIONS. 
Average measurements of specimens from Arctic America. Length, 13 - 75; stretch, 23'50; wing, 7‘40; tail, 4 - 65; bill, 
’63; tarsus, l - 22. Longest specimen, 14'50; greatest extent of wing, 24’00; longest wing, 7'50; tail, P85; bill, '70; tarsus, 
1-35. Shortest specimen, 12’80; smallest extent of wing, 23 , 09; shortest wing, 7‘00; tail, 4’50; bill, - 65; tarsus, 110. 
DESCRIPTION OF NESTS AND EGGS. 
Nests, placed on the ground. They are not very elaborate structures, being composed of leaves, grass, or any other 
convenient material. 
Eggs, from eight to fifteen in number, oval inform, reddish-buff in color, spotted and mottled with irregular blotches 
of purplish-brown. Dimensions, from 1‘lOx P55 to l - 12x 165. 
HABITS. 
The Rock Ptarmigan, according to Audubon, was common about the Bras d’Or dur¬ 
ing the cold season but retreated into the interior of the country during summer to breed, 
nesting in June. There appears to be some confusion regarding the distribution of this 
species, for it has frequently been confounded with the preceding, perhaps with good rea¬ 
son. It is probable, however, that these birds have much the same range, especially in 
summer, although the one under consideration appears to be much less common in Canada, 
for out of a large number of white Ptarmigans which I have examined from that section, I 
never saw an undoubted specimen of the Rock Ptarmigan. The habits of both are described 
as being similar, excepting that Audubon is inclined to believe that the present species 
inhabits more open ground than does the one last described. 
GENUS III. CUPIDONA. THE PRAIRIE GROUSE. 
Gen. Ch. Posterior margin of sternum, between indentations, widened and rounded. Tip of keel, projecting forward. 
Costal process, narrow and rounded at point. 
