GLOSSARY. 
Nearly all the terms used in describing a bird may be more easily 
and clearly understood by examining the accompanying figure than from 
a written description; a few, however, may, perhaps, require a word of 
explanation. 
MANDIBLES. — Some authors use the word max7//a for the upper half of 
the bill, and mandible for the lower. I prefer, however, to describe the 
two halves of the bill as upper and lower mandible, 
CULMEN. — The ridge of the upper mandible. 
GONYS. — Lower outline (middle) of under mandible. 
UNGUIS.— The nail on the end of the upper mandible ; very pronounced 
in several families of water birds,__ Ducks, Pelicans, and Petrels. 
AXILLARS or AXILLARY PLUMES. — Several elongated feathers at 
the junction of the wing and body (Lat. avi//a, the arm-pit). 
SPECULUM. — A wing band or patch (usually of a different color from the 
rest of the wing) formed by the terminal portion of the secondaries ; very 
noticeable in the Ducks. 
TARSUS. — Extends from the root of the toes to the end of the #/d/a (what 
appears to be the bend of the leg or knee; but which is, in reality, the 
heel joint). 
SUPERCILIARY STRIPE. — Stripe over the eye. 
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