100 
ROCK PTARMIGAN. 
ders, are pure white, the shafts of the former black, 
and having sometimes a brownish-black tint accom- 
panying their length ; the tail contains sixteen 
feathers ; the outer pair are edged with white along 
the outer weh, and, with the next six, on each side, 
are dull black ; the centre, or eighth pair, are grey, 
mottled with dull black, white at the tips, where 
they are also slightly worn ; the upper covers reach 
within a quarter of an inch of the end of the 
tail. On the cheeks, throat, neck, and breast, the 
yellow and pale markings predominate to a greater 
extent, and on the latter assume more the form of 
bars ; on the belly, flank, and other lower parts, the 
yellow markings still prevail, and assume a greater 
space in the form of transverse broken masses, while 
in the lower part of the breast, and centre of the 
belly, there are many pure white feathers, which 
give a paler or more hoary shade to these parts ; 
the tarsi and half of the toes only are strongly 
feathered ; the nails are brownish-black, paler at 
the base. 
On comparison, our specimen will be seen to be 
nearly two inches shorter, in extreme length, than 
that of Dr. Richardson and Mr. Swainson’s birds, 
the markings running in them more in bars. In 
our Scotch specimen, also, there are occasionally 
feathers interspersed, having the grey and white 
markings of the young birds, and males, in autumn 
plumage ; but whether the Rock and Common Ptar- 
migan may be found to be distinct or not, we have 
little doubt that the female of the former, in the 
