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 carulescens. 



Blue Goose. 

 See No. 69. 



Subfamily CYGNIN^E. 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. 



