BLACK GROUSE. 147 



part of the back also large and rounded ; on the rest of the back 

 smaller, oblong, but with a broad extremity ; on the breast 

 nearly of the same form ; on the sides elongated ; on the ab- 

 domen rather downy ; under the tail large and full, some of 

 the coverts extending about an inch beyond the middle of the 

 tail-feathers; the upper tail-coverts only about half an inch 

 shorter ; on the legs short, with disunited filaments ; on the 

 tarsi short and soft anteriorly, longer and hair-like on their 

 sides. The lustre is ordinary, but the feathers of the head, 

 neck, and hind part of the back, are highly glossed, and have 

 a silky smoothness. 



Over the eye is a bare space, an inch and a twelfth long, half 

 an inch in height, covered with long tapering, flattened papillae, 

 and without an upper free margin. The eyes are of moderate 

 size, the eyelids thinly covered with very small feathers, and 

 having a narrow crenate margin. The aperture of the ear is 

 circular, four-twelfths of an inch in diameter, with a thickened 

 slightly elevated margin. The nostrils are oblong, with a thick 

 arched opercular margin, and concealed by the feathers which 

 cover the nasal membrane. 



The bill is very strong, but proportionally not larger than in 

 the Brown and Red or Willow Ptarmigans, and many other 

 species belonging to all the sections of the genus. The upper 

 mandible is deeply siriuate in its basal outline ; its dorsal out- 

 line is nearly straight at the base, towards the end arcuato-de- 

 clinate, the ridge broad and convex, the sides convex towards 

 the end, the edges nearly straight and ascending to beyond the 

 nostrils, then declinate, sharp and overlapping, the tip rounded 

 and thin-edged. The lower mandible has the angle broad and 

 rounded, the dorsal outline slightly convex, the back broad, 

 the sides convex, the edges arched, thin, erect, the tip rounded. 



The upper mandible is concave within, with a central and 

 two lateral prominent lines ; the lower deeply concave, with a 

 broad central and two lateral grooves. The mouth is rather 

 narrow ; the palate flat, anteriorly covered with pointed pa- 

 pillae arranged in transverse series, posteriorly with smaller 

 scattered papillae ; the space corresponding to the tongue bound- 

 ed by two lateral longitudinal lines, having a transverse papil- 

 la 2 



