TETRAO. 77 



merly all included under that title, but have, by 

 modern ornithologists, been sub-divided, both on 

 account of a difference of habit, and a modifi- 

 cation in the form of several of the parts, and 

 Tetrao is now kept for those large and power- 

 ful species, with expanded tails and naked feet, 

 which are polygamous, and dwell in shaded 

 forests or wooded districts. Once we possessed 

 a truly typical species, for the recovery of which 

 great exertions are making; but the true forms are 

 now chiefly found in Northern Europe and Ame- 

 rica, though a very near example of the general 

 shape and appearance may be seen in the female 

 of our black cock, the greatly developed tail of the 

 male presenting a variation, which has been con- 

 sidered by some as of sub-generic importance. 



TETRAO of modern ornithologists. Generic cha- 

 racters. Bill short, very strong and arched 

 from the base; nostrils basal, lateral, and 

 hidden from view by closely set feathers ; a 

 naked skin above the eyes, enlarging in spring, 

 and coloured brightly ; wings short, concave, 

 third and fourth quills longest; tail very ample 

 and expanding, (rounded*;) feet naked, with 

 the edges of the toes fringed ; tarsi feathered. 



Types, T. urogallus, obscurus. Europe, Northern 

 Asia, North America. 



* If Lyrurus be kept as a sub-genus, " rounded" should be 

 inserted in the characters. 



