AUKS, MURRES, PUFFINS, ETC. 33 



son, showing in flight, or often as the bird 

 dives, for it springs upward before plunging 

 beneath the water. It is rather shy, even on 



* Fig. 23. 



Black Guillemot; figure ID front, summer; behind, win- 

 ter, dress. 1-6. 



its breeding grounds. Although the winter 

 dress shows considerable white, this species 

 ma3 r be distinguished from the ducks which 

 show about as much white, like the Buffle- 

 head and Oldsquaw, by the pointed bill and 

 habit of carrying the head well forward when 

 swimming. Guillemots, when at a distance, 

 quite closely resemble floating bottles. 



The Black Guillemot breeds from the 

 coast of Me. northward, nesting in rock cav- 



