INTRODUCTION. 3 



or riding on the waves ; while far away at sea, 

 upborne on outstretched wings, the Albatrosses 

 sweep along over degrees of longitude, and circle 

 round the globe itself, in the unbounded freedom 

 of their flight. 



Presenting so much variety in their occupations 

 and mode of life, it may naturally be supposed that 

 a corresponding diversity exists in the structure of 

 their limbs, and in their means of procuring their 

 subsistence. The feet and claws of a perching bird 

 could never be available for swimming, nor could 

 the bill of a Snipe be used for the same purposes as 

 the beak of an Eagle. In the classification of birds, 

 therefore, the ornithologist is guided by certain 

 characters, derived from their general shape and 

 proportions, the structure of the mouth, bill, tongue, 

 wings, tail, and legs, all of which are necessarily in 

 relation with particular habits ; and his constant 

 endeavour is to detect and define, with brevity and 

 precision, the most prominent features whereby 

 different races are distinguishable. 



In order to render such descriptions intelligible 

 to the general reader, it will be necessary, not only 

 to map out, as it were, the several parts that charac- 

 terize the objects of our study, but to employ words 

 and phrases of distinct and limited meaning, as 

 expressions of the peculiarities they exhibit ; we 

 need, therefore, scarcely apologize for introducing 

 our subject by a few preliminary remarks relative 

 to the nomenclature adopted in the following pages. 



The Head of a bird consists of the slmll, and the 

 hill or healx, and is joined to the body by the ^lech. 



The Beak or Bill consists of an upper jaw, called 

 in ornithological language the TJp]jer MandAhle (Fig. 

 1, 12)^ and of the lower jaw, or Lower Mandible (13). 



The Upper Mandible contains the orifices of the 

 nostrils (c), the shape of which varies in diff'erent 

 birds. Its highest part is called the Culmen (t), 

 while the corresponding ridge of the lower mandible 

 is termed the Gonys (h). 



