DUSKY GROUSE. 299 



delicacy and lightness. Such are the Bonasice, T. umhellus of America, 

 and T. honasia of Europe. 



The Grouse are distinguished by a short stout bill, feathered at base, 

 and they are of all gallinaceous birds those in which the upper mandi- 

 ble is the most vaulted : the feathers of the bill are very thick and 

 close, and cover the nostrils entirely. The tongue is short, fleshy, 

 acuminate, and acute. The eye is surmounted by a conspicuous red 

 and papillous naked space. The tarsi are generally spurless in both 

 sexes, and partly or wholly covered with slender feathers, which in the 

 Lagopodes are thicker and longer than in the rest, extending not only 

 beyond the toes, but growing even on the sole of the foot ; a peculiarity 

 which, agreeably to the observation of Buffon, of all animals is again 

 met with only in the hare. These feathers in winter become still longer 

 and closer. All the others have the toes scabrous beneath, and fur- 

 nished with a pectinated row of processes each side.* This roughness 

 of the sole of the feet enables them to tread firmly on the slippery sur- 

 face of the ground or frozen snow, or to grasp the branches of trees 

 covered with ice. Their nails are manifestly so formed as to suit them 

 for scratching away the snow covering the vegetables Avhich compose 

 their food. The wings of the Grouse are short and rounded, the first 

 primary is shorter than the third and fourth, which are longest. The 

 tail is usually composed of eighteen feathers, generally broad and 

 'rounded. The Red Grouse, T. scoticus, however, and the European 

 Bonasice, and T. canadensis or Spotted Grouse, have but sixteen ; while 

 our two new North American species have twenty, one of them having 

 these feathers very narrow and pointed, the narrowness being also 

 observed in the Sharp-tailed Grouse. They have the head small, the 

 neck short, and the body massive and very fleshy. 



The females of the larger species difier greatly from the males, which 

 are glossy black, or blackish, while the former are mottled with gray, 

 blackish, and rufous : such are all the typical Tetraones of Europe, and 

 the Cock of the Plains, the Dusky, and the Spotted Gi'ouse of America. 

 The smaller species, in which both sexes are mottled, such as T. phasi- 

 anellus and T. cupido, exhibit little or no difference in the plumage of 

 the two sexes ; which is also the case in all the Bonasice and Lagopodes. 

 The young in their first feathers are in all respects like the female, and 

 the males do not acquire their full plumage until after the second moult. 

 All moult twice a year, and most of the Lagopodes change their colors 

 with the seasons in a remarkable manner. 



The genus Tetrao is now composed of thirteen species, three Lago- 



* These processes are liable to fall off, at least in preserved skins. It is owing 

 to this circumstance that we committed several errors in characterizing these birds 

 in our Synopsis of the Birds of the United States. 



