4 BIRDS OF EASTERN NORTH AMERICA. 
The Speculum. A term used to indicate a patch or band on the wing (usually of 
different color from the rest of the feathers), formed by the terminal portion 
of the secondaries, very noticeable inthe Ducks. (See illustration, Topography 
of a Duck, page 8.) 
Onder Primary, Coverts 
oe 
- 
— 
LEZ torn Atry Pama 
Under Surface of Wing. 
an important aid in the identification of 
The Axillary Plumes, or Axillars, are 
elongated feathers growing from the arm- 
many species; these are several rather 
pit (avila), at the junction of the wing and body. 
THE TAIL. 
The Rectrices, or Tail Feathers, proper, number from 8 to 24, and in some very few 
‘ases even more. By far the greater number of birds, however, have 12 rectrices. 
Pointed or cuneate tail Forked tail 
Graduated tail 
The small feathers overlapping the rectrices are called upper tail coverts, while 
those below are the under tail coverts or crissum,. (For illustration of tail 
coverts and erissum, see Topography of a Bird.) 
