278 THE THIBETAN SNOW-COCK. 



means representing fully the limits within which adults vary, 

 As for the young they are much smaller. 



Males. — Length, 1 9'0 to 21*5 ; expanse, 30*0 to 32*5; wing, 

 100 to io-6 ; tail from vent, 6'S to 74, ; tarsus, 2*1 to 2*36 ; 

 bill from gape, 1*3 to 1-4. Weight ? 



Females. — Length, i8 - o to 20*0 ; expanse, 29*0 to 31*5 ; wing, 

 9*55 to 10-2; tail from vent, 64 to 7-0; tarsus, 2"i to 2*2; 

 bill from gape, 1*15 to 1*3. Weight ? 



The irides are brown or reddish brown ; orbits red ; the legs 

 and feet vary, in both sexes as far as I can make out, from orange 

 through every shade to almost coral red — possibly according to 

 season, more probably according to age ; the bill is dull red to 

 orange horny in the male, often dusky about the base (a sign 

 I fancy of nonage), and greenish or yellowish green in the 

 female, always apparently dusky towards the base, and paler 

 and yellower on the lower mandible. 



The Plate is particularly good, but unfortunately represents 

 the male bird only. 



Prjevalsky correctly exposes the error into which Mr. Gould 

 and I fell in stating that the males and females of this species 

 are alike. I had never myself sexed a specimen, and had to 

 rely on others ; broken reeds as it turns out. 



As a matter of fact the female has only a central stripe 

 down the throat white, and has the whole cheeks, sides and 

 front of the neck, and breast as far down as the grey band 

 extends in the male, finely mottled, vermicellated, and variegated, 

 brown and rufous buff, the brown being much darkest on the 

 sides of the neck and in front at its base, and becoming grey- 

 er towards where this crop patch ends. 



In the males the bills are reddish to orange horny ; in the 

 females greenish horny, yellower on the lower mandible, dusky 

 about the base. 



The bill in the male is considerably larger than in the 

 female, and he has a large, very stout, very blunt spur on each 

 leg, while the females and younger males (though apparently 

 nearly full sized and quite full plumaged) have no trace of 

 this. 



Prjevalsky also says : — " A male from Kansu has under the 

 throat a large slate coloured spot, not an uninterrupted cross 

 band running parallel to the breast band, as described by 

 Hume, but not marked at all by Gould." 



Gould, I expect, figured from an indifferent specimen or the 

 birds may be variable in this respect,* but I have never yet seen 

 any male entirely wanting this throat band. Of five adult males 



* Hodgson figures a specimen, not only without the throat band, but with only 

 a trace, just a few scattered feathers here and there, of the breast band. 



