NOTE. 



The necessity for beginning this work with the highest instoiul of 

 the lowest forms is to be regretted, and may be explained by briefly 

 stating that owing to inadequate facilities for properly arranging the 

 larger birds in the National Museum collection these are not available 

 for study, and consequently it became necessary either to begin with 

 the smaller birds, already systematically arranged, or else postpone 

 the work indefinitely. 



The descriptions arc limited to essential characters, but extreme 

 brevity has been avoided in order to render identification more certain. 

 In the case of subspecies, however, only those characters which are 

 peculiar to each are mentioned, the fuller description of the first in a 

 group of conspecific forms applying to all of those which follow, except 

 as modified by the diagnosis pertaining to each of the latter. 



Measurements are in millimeters, and are made in the following 

 manner: 



(1) Length, from tip of bill to tip of tail of the dried skin. This 

 measurement is really of little value, and is given merely as a sort of 

 clue to the general size of the bird. It varies greatly in the same 

 species according to the "make " of the skin,' and is usually materially 

 different from the same measurement before skinning. 



(2) Wing, measured with dividers, one point resting against the 

 anterior side of the bend the other touching the extremity of the 

 longest primarj^ 



(3) Tail, measured with dividers, one point of which is inserted 

 between the shafts of the middle pair of rectrices at the base and 

 pressed forward as far as they will go without splitting the integu- 

 ment, the other point touching the extremity of the longest rectrix. 



(4) Cuhnen, measured with dividers, either from the extreme base 

 or exposed base — that is, the base as seen without parting the frontal 

 feathers — the character of the measurement always being indicated as 

 "culmen from base" and "exposed culmen." 



(5) Depth of Mil at hase, measured with dividers from lower edge 

 of mandibular rami to highest portion of the culmen. 



' Specimens of conspicuously extended or abbreviated make liave, however, been 

 excluded from measurement. 



