JAN., 1909. BIRDS OF ILLINOIS AND WISCONSIN CORY. 73 



General plumage, grayish; rump, white; larger than C. hyper- 

 borea (immature). Eastern North America, south in winter to 

 Florida and Cuba. Chen hyperborea nivalis. 



Greater Snow Goose. 

 See No. 68a. 



Head, brownish gray; chin, white; rump, gray; unguis (nail of 

 bill), yellow; wing coverts, grayish, showing very little white on the 

 edge of the feathers (immature). Chen c&rulescens. 



Blue Goose. 

 See No. 69. 



Subfamily CYGNIN^. Swans. 



Size, very large ; bare skin, between the bill and eye ; tarsus, reticu- 

 late (scales rounded); neck, very long; wing, over 19 inches long; 

 hind toe, without flap. 



General plumage, white; bill, black, with yellow spot (adult); 

 distance from tip of bill to nostril, less than distance from nostril to 

 eye (immature birds are gray or brownish gray). Olor columbianus, 



Whistling Swan. 

 See No. 73. 





Whistling Swan. 



General plumage, white; bill, black, showing no yellow; distance 

 from tip of bill to nostril, more than distance from nostril to eye. 

 Chiefly found in the interior of North America; (immature birds are 

 gray or brownish gray ) . Olor buccinator. 



Trumpeter Swan. 

 See No. 74. 



