LAGOPUS RUPESTR1S. 349 



visitants. They arc, however, found commonly mi Newfoundland and in Labrador, migra- 

 ting thrncc, during winter, into Canada, reaching, perhaps, the New Kngland Stai.-s \,TV 

 rarely. Tho Willow Grouse, as they are sometimes called, inhal.it tlie harren heaths and 

 cold swamps of the countries of which I have spoken, and from these are distributed north- 

 ward into the Arctic Zone. A.s 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 rupritri.i I.KUII, /Cool. Misc., II, 290. 



l>KSrlMITIO\. 



SP. Cn. Form, robust. Size, large. Tail ami wings, long. Bill, rather slender, exceeding in length, measured from 

 nostril to tip, tln> height at bae. .Sexes, quite similar. 



COLOR. Adu.ll in winl'T. White throughout, excepting tail which is blnck with the central feathers and tips of all 

 white, and there is a black line from bill through eye. 



Adult in suinmir. Ah.ive, black, barred and spotted with yellowish-red; lighter below and broadly and regularly band- 

 ed with yellowish-red; otherwise as iu the male. Bill, black, iris, brown, claws, born color, in all stages. 



OBSERVATIONS. 



Known from the closely allied albus by the black band through eye, and more slender hill, this lieing longer than high 

 at ba-e. Both species of Ptarmigans may be known from all other Grouse by tin- wholly feathered tarsus and feet. Dis- 

 tributed in summer, throughout Arctic Americ.i, 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, 

 <>3; tarsus I 1 'JO. Longest specimen, 14'50; greatest extent of wing, -JlMM); lonirc-t wing, 7'50: tail, 4 - 8o; bill, '70; tarsus, 

 1-35. Shortest specimen, 12'80; smallest extent of wing, 23'OH; shortest wing, 7'00, tail, 4'50; bill, '65; tarsus, 1-10. 



DESrl;ilTlo\ OF NESTS AND K.cci.S. 



Nests, placed on the ground. They are not very elaborate structures, being composed of leaves, gmt>, or any other 

 convenient material. 



<, from eight to fifteen in number, oval in form, reddish-buff in color, spotted and mottled with irregular blotches 

 of purplish-brown. Dimensions from l'lOzl'55 to ridx 1 ti5. 



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 goo' ! 

 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, 1 

 ne\ or 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. 



CKXUS III. (TPinoXA. TI1K PK.UIMK. Hi:". 



(!ES. CH. Posterior mary in uf sternum, between indentations, tetdened anil rounded. Wp of keel, projecting forward. 

 Coital procest, narruw and rounded at point. 



