DIRECTORY TO BIRDS OF EASTERN NORTH AMERICA. 



EXPLANATION OF DIAGRAM OF CHIPPING SPARROW. 



A, EXTERNAL PARTS:- 1, bill; 2, forehead; 3, crown; 

 4, occiput; 5, nape; 6, hind neck; 7, back; 8, wing; 9, up- 

 per tail coverts ; 10, under tail coverts; 11, tibia; 12, abdo- 

 men; 13, belly; 14, breast; 15, throat; 16, chin; 17, supercil- 

 iary region; 18, lores; 19, ear coverts; 20, maxillary region; 

 22, tarsus ; 32, hind toe ; 42, front toe ; 52, tail. 



INTERNAL PARTS:- A, tongue; B, larynx; p, syrinx; c r 

 windpipe; E, sterno trachealis; F, bronchial tube; G G, gul- 

 let; H, crop; K, stomach; j, proventriculus*, L, fold of duo- 

 denum; M, pancreas; o, vent; D, ovaries; Q, vertebrae of 

 neck; R, vertebrae of back; s, tail bones; T, heart; N, lungs; 

 v, keel; i M, liver. 



B, WING OF CHIPPING SPARROW:- 1, lesser coverts; 2 r 

 middle coverts; 3, greater coverts; 4, spurious wing; 5, pri- 

 maries; 6, secondaries. 



C, BILL OF CARDINAL GROSBEAK:- A, upper mandible; 

 B, lower mandible; D, nostril. 



