84 



KEY TO THP: birds OF EASTERN NORTH AMERICA 



SUBFAMILY CYQNIN/E. 

 Swans. 



Bare skin, between the bill and eye ; tarsus, reticulate ; neck, very long ; 

 wing, over 19 inches long. 



General plumage, white; bill, black witli yellow sput (adult) ; distance from tip of bill 

 to nostril, less than distance from nostril to eye (immature birds are gray or brownisb i;ray). 

 Common on some parts of the coast. Olor Columbian as. Whistling Swan. 



See No. VM\. 



General plumage, white; bill, black, showino- no yellow; distance from tip of bill to 

 nostril, more than distance from nostril to eye. Chiefly found in the interior of North America ; 

 not common on the coast. Olm- hnccinaior. Trumpeter Swan. 



See No. 137. 



Olor colunibianus. ' 



General plumage, gray, or brownish gray; birds of this description may be the 

 youMij of cither of the above species, the ditterence in the distance from the bill to the eye 

 being characteristic as in the old birds. 



