OF THE GENVS TETRYO. 387 



longest. The tail is usually composed of eighteen feathers, 

 generally hroad and rounded. The Hed Grouse, however, T. 

 scofkus. as well as the T. honasia. and the T. canadensis. 

 have hut sixteen, while the two new North American species 

 have twenty: one of the latter, moreover, has these feathers 

 very narrow and pointed, a character which is also found 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 differ greatly from the 

 males in colour, the latter being glossy black, or blackish, 

 whilsl tlie former are mottled with gray, blackish, or ru- 

 fous: such are all the typical Tef wanes of Europe, and 

 the cock of the plains, the dusky, and the spotted Grouse of 

 America, the latter being of smaller size. The smaller, mot- 

 tled species, such as T. phasianellw and T. enpido. exhibil 

 little <>r no difference in the plumage of the two sexes, which 

 is also the case in the Bonasise and Lagopodes. The young 

 in their first feathers are like the female in all the species, 

 and moult, twice before they obtain their fidl plumage. All 

 have a double moult, and most of the Lagopodes vary in a 

 remarkable degree with the seasons. 



The genus Tdrao comprises thirteen species, of which we 

 consider eight as typical, two we arrange under Bonasia. and 

 three under Lagopus*. The species of Lagopas. as might 

 be expected from their high northern habitation, are common 

 to both continents, with the exception of the Hed Grouse, 

 which is peculiar to the British Isles; and which, from the 

 circumstance of its not changing its colour with the season, 

 forms the passage to the true Til ramus. Of these, five inha- 

 bit North America, and three Europe, none being common 



to both. Of the two BoTUMW, one IS peculiar to the Old. and 

 the other to the New continent. Thus we find, that of the 

 entire genus, eighl are distributed to America, and seven to 



* Even the modern Tetrao rupettris we do not consider well established: as 

 for thai of former authors, it i- undoubtedly '/'. lagopus. We arc equally scepti- 

 cal with r<L'iril to '/'. ulandiau and T. montanu.s of Brehm. 

 \ iM„ lit. 5 F 



