654 GEOLOGICAL SURVEY OF THE TERRITORIES. 
and also from the author’s observations, both in the field and from speci- 
mens in his own collection. _ : 
Among gallinaceous. fowls the Grouse are known by certain char- 
: acters, such as 
the narrow and 
naked supra-pal- 
petral processes; 
by the feathers 
filing the exter- 
nal nasal fossz ; 
by the cervical 
and inflatable air- 
sacs of Cupidonia 
and others; and 
finally by the 
feathered tarsi, 
the naked toes, 
with the peculiar 
horny processes, 
fringing their 
edges In Lago- 
pus the feathers of the tarsi are dense, and carried to the very claws, 
this genus thus forming an exception to the last observation. 
In the arrangement of the genera we adopt the high authority of the 
authors of the History of North American Birds (A Hist. N. A. Birds, 
Boston, 1874, Baird, Brewer, and Ridgway). In this work we find the 
following divisions given us, with some few modifications, which the 
reader will readily recognize: 
Centrocercus urophasianus- 
( [ ( Species: 
| 1. Canace canadensis. 
Subgenus Canace. (Spruce Grouse.) 
}2. Canace canadensis frank- 
( lini. (Franklin's Grouse.) 
1. Genus Canace. (American } : (1. Canace obscura. (Dusky 
Wood Grouse.) | | Grouse.) ; 
, | 2. Canace obscura fuliginosa. 
| Pubgenue Dendra- (Oregon Dusky Grouse.) 
BaP US: 3. Canace obscura richard- 
| soni. (Richardson's Dusky 
{ lL Grouse.) 
@ Species: 
1. Bonasa umbella. (Ruffed Grouse.) —~ 
| 2. Genus en (Cae | 2. Ronasa umbella nmbelloides. (Gray Ruffed 
A : rouse. TOUSE.) 
eT aReLent | 3. Bonasa umbella_ sabinii. (Oregon Ruffed 
; | ( Grouse.) 
| [ Species: 
3. Genus Lagopus. (The Ptar-} 1. Lagopus albus. (The Willow Ptarmigan.) 
migans.) \ 2. Lagopus rupestris. (Rock Ptarmigan.) 
(3. Lagopus leucurus. (White-tailed Ptarmigan.) 
‘ ( Species: 
he Genus Cupidonia. (Pin-j1. Cupidonia cupido. (Prairie Chicken.) 
nated Grouse.) \ 2. Cupidonia cupido pallidicincta. (Lesser Prairie 
| l Ohicken.) 
( Species: : 
\e Genus Pediwcetes. (Sharp- } Ree eee ne (Morpher TS aa 
NE, ERED) | 2. Pedicecetes phasianellus columbianus. (Com- 
| l mon Sharp-tailed. Grouse.) 
6. Genus Centrocercus. ne Species: : 
l Cock ; Cock of the Plains.) ) 1. Centrocercus urophasianus. (Sage Cock.) 
For the two subgenera of Canace, the principal differences seem to 
be, that the first, Canace, differs from the second, Dendragapus, in that it 
is of smaller size; has sixteen tail-feathers to twenty of the latter, and 
also Canace has no inflatable air-sac at the sideof the neck, which the 
subgenus Dendragapus has. Otherwise the varieties of each subgenus 
