INTRODUCTION. 
'HE present volume is intended to supply a want 
X much felt by the author during the course of his 
ornithological studies, and therefore presumably experi- 
enced by other workers in the same field ; namely, a nomen- 
clature of colors and a compendious dictionary of technical 
terms used in descriptive ornithology, together with a 
series of plates or diagrams illustrating the external anat- 
omy of a bird in relation to the terms employed, and such 
other things as are more clearly expressed by a picture 
than by a mere definition. Probably few, if any, natural- 
ists have not on more than one occasion deplored the 
absence of such an aid to their studies ; for it is very 
difficult, if not impossible, for any one to keep all these 
things clearly in mind. 
Undoubtedly one of the chief desiderata of naturalists, 
both professional and amateur, is a means of identifying 
the various shades of colors named in descriptions, and of 
being able to determine exactly what name to apply to 
a particular tint which it is desired to designate in an 
original description. No modern work of this character, 
it appears, is extant, — the latest publication of the kind 
which the author has been able to consult being Syme's 
edition of " Werner's Nomenclature of Colors," published 
