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TETRAO OBSCURUS. 
genus Tetrao . I. — Lagopus, which represents it in the 
Arctic Polar regions ; for whose climate they are 
admirably adapted by being clothed to the very nails 
in plumage suited to the temperature, furnished abun- 
dantly with thick down, upon which the feathers are 
closely applied. The colour of their winter plumage 
is an additional protection against rapacious animals, 
by rendering it difficult to distinguish them from the 
snows by which they are surrounded. II. — Tetrao , 
which is distributed over the more temperate climates ; 
the legs being still feathered down to the toes. III. — 
JBonasia, a new division, of which we propose Tetrao 
bonasia , L. as the type, in which only the upper portion 
of the tarsus is feathered. These occasionally descend 
still farther south than the others, inhabiting wooded 
plains as well as mountainous regions, to which those 
of the second section are more particularly attached. 
But the entire genus is exclusively boreal, being only 
found in Europe, and the northern countries of America 
and Asia. The long and sharp-winged grouse, or 
Pterocles of Temminck, which represent, or rather 
replace these birds in the arid and sandy countries of 
Africa and Asia, a single species inhabiting also the 
southern extremity of Europe, w r e consider, in common 
with all modern authors, as a totally distinct genus. 
That group, composed of but few species, resort to the 
most desert regions, preferring dry and burning wastes 
to the cool shelter of the woods. These oceans, as they 
might be termed, of sand, so terrific to the eye and the 
imagination of the human traveller, they boldly venture 
to cross in large companies in search of the fluid so 
indispensable to life, but there so scarce, and only 
found in certain spots. Over the intervening spaces 
they pass with extraordinary rapidity, and at a great | 
elevation, being the only gallinaceous birds furnished 
with wings of the form required for such flights. This, 
however, is not the only peculiarity in which they 
aberrate from the rest of their order, and approach the 
pigeons, being said to lay but few eggs, the young 
