^°/'o^^1 DuTCHER AND Baily, Htibits of the Herring Gull. A in 



side view of head of three nestling stages — primaries 4 

 mm., 13 mm, and 32 mm. long, respectively ; 26, Coconiis 

 agassizi, dorsal pterjlosis. 

 Plate XIX. Alimentary Canals. — Fig. 27, Geospiza conirostris cotii- 

 rosiris (length 205 mm ); 28, G. fuligiuosa parviila (length 

 170 mm.) ; 29, G. fortis dubia (length 204 mm.) ; 30, G. 

 crassirostris (length 255 mm.) ; 31, G. scandens fatigata 

 (length 200 mm.); 32, Certhidia olivacea Ititeola (length 

 102 mm.) ; 33, Cocornis agassizi (length 125 mm.). 

 Plate XX. Tongues. — Fig. 34, Geospiza scandens fatigata ; 35, G. 

 kabeli; 36, G. fortis fortis; 37, G. scandens fatigata; 38, 

 G. prostkemclas; 39, Cocornis agassizi, tip of tongue; 40, 

 Geospiza fuliginosa fa rviila; 41, Certhidia olivacea luteola; 

 42, Cocornis agassizi. 



A CONTRIBUTION TO THE LIFE HISTORY OF THE 



HERRING GULL {LARUS ARGENTATUS) IN 



THE UNITED STATES. 



BY WILLIAM DUTCHER AND WILLIAM L. BAILY. 



Plates XXI ami XXII. 



The facts presented in this paper are the results of several 

 visits to the large breeding colonies of Herring Gulls on the 

 Maine coast, made at the following dates: by Mr. Dutcher, 1900, 

 from June 28 to July 21 ; 1901, by both contributors, from June 12 

 to 24; 1902, by Mr. Baily, from July 18 to 20 inclusive. In 1900 

 visits were made to nearly all of the colonies along the Maine 

 coast by the senior contributor, commencing at the most westerly 

 one on No-Man's-Land Island, which is situated about seventeen 

 miles south of Rockland, Maine, and adjoins the large island 

 known as Matinicus. In 1901 eight days were spent at the light- 

 house station on Great Duck Island, and subsequently nearly all 

 of the other colonies were revisited by Mr. Dutcher. In 1902 Mr. 

 Baily revisited the Great Duck Island colony later in the season, 

 in order to observe the methods of feeding the young birds and 

 the habits of the young. A description of the position and 



