iN'n?or>ucTioN. 



Tlie shape and size of the bill vary greatly, as will be seen by the following 

 illustrations representing fifteen of the principal types among our birds : — 



Bill of Whiitpocirii'M 



Bill in' liiitnmmn-hirfi 



Bill 0/ ^^l,rH-c 



Cere. A membrane (usually hard), which covers the base of the upper mandible. 



(Hawks, Parrots, Jivgers.) 

 Nasal Fossa, or Nasal Groove. Groove in which the nostrils open. 

 Qonys. Lower outline (middle) of the under mandible, A to B. 

 Culmen. The ridge of the upper mandible. 

 Unguis. The nail ou the end of the upper maudible. Very pronounced in some 



families of Water Birds, — Ducks, Pelicans, and Petrels. 

 ilandibles. — Some authors use the word uia.riJla for the upper half of tlie bill, ami 



mandible, for the lower. I prefer, however, to di'scribe the two halves of the bill 



as upper and lower maudible. 



