98 
ROCK PTARMIGAN. 
cal with the northern specimens of L. rupeslris , com- 
paring it at the time with the northern specimens 
in the Edinburgh Museum. In the Northern Zoo- 
logy the description of the male is given, “ colour, 
snow-white ; shafts of the six greater quills and 
fourteen tail-feathers, pitch black, the latter nar- 
rowly tipped with white ; bill black ; nails whitish, 
dark at the base ; male, with a black eye stripe from 
the nostrils to the hind head; form , bill narrower 
at the base, and more compressed throughout than 
that willow grouse, also larger and narrower than 
that of the T. lagopus* (Scotch specimen) ; third 
and fourth quills the longest ; tail very slightly 
rounded, consisting of sixteen feathers, fourteen 
black ones, and two white incumbent ones, which, 
with a pair of the coverts, are rather larger than 
the rest of the tail ; tarsi and toes feathered as in 
the willow grouse ; the nails more compressed, but 
otherwise similar to the latter.” 
“ Summer plumage . — A female killed on the 
rocky mountains, latitude 55°. Head, neck, back, 
scapulars, tertiories, part of the intermediate coverts, 
and the under plumage, barred with blackish-brown 
and brownish-yellow, the dark colour predominating 
above, and the yellow beneath ; most of the dorsal 
plumage bordered on the tips with brownish-white ; 
the remainder of the wring above, its whole surface 
beneath, and the auxiliaries, white ; the quill shafts 
slightly tinged with brown ; the vent feathers yel- 
* L. mutus. 
