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rous supply of offal. Arrives from the. north during October, and the 

 adults, with the greater portion of the young, move north the middle 

 of April. I do not think that the young breed until they don the per- 

 fectly adult plumage, for, in June, 1876, I found a large flock consist- 

 ing of about two hundred immature gulls, nearly all of this species, 

 upon the Lake shore near Waukegan, and upon making inquiries 

 learned that each year about the same number were in the habit of 

 remaining at this place through the summer. The flock contained 

 birds in every stage of plumage between the last year's young and 

 the adult birds, of which a few were present. The large number of 

 fishing nets set at Waukegan explained their preference for that 

 locality. A colony of these birds breed on an island in the channel 

 between Lake Michigan and Green Bay, and many others at various 

 plates on Lake Superior. 



296. L. delewarensis Ord. KING-BILLED GULL. Common mi- 

 grant along the Lake. Very rarely remains through the winter. 

 Most common with us September 20th to November 30th, and March 

 20th to the first of May. A few young of this species were, with the 

 flock of young herring gulls, observed at Waukegan in June. 



297. L. tridactylus Linn. COMMON KITTIWAKE GULL. A rare 

 winter visitant to Lake Michigan. Dr. Hoy writes that in the winter 

 of 1870 a single specimen of this species kept about the harbor for 

 several days, but was too shy to be shot. He is quite certain of his 

 identification, as he examined the bird carefully with a large field 

 glass, while it was standing upon a piece of ice just out of gun shot. 



298. L. atricilla (Linn.). LAUGHING GULL. "Summer visitant" 

 (Ridgway). I give this species entirely upon the strength of its oc- 

 currence in Mr. Eidgway's Catalogue (Ann. K. Y. Lye. N. H., Jan.,. 

 1874). 



299. L. franklini Rich. FRANKLIN'S GULL. A rare visitant to 

 Lake Michigan. A specimen was obtained at Milwaukee in 1850, and 

 is preserved in a collection at that place (Hoy). This species un- 

 doubtedly is of more or less regular occurrence during the migrations 

 in company with the immense numbers of L. Philadelphia which pass 

 along the Lake to their breeding grounds. 



300. L. Philadelphia Ord. BONAPARTE'S GULL. Exceedingly 

 abundant migrant. Arrives in large numbers, and usually in full breed- 

 ing dress, the 5th to 10th of April, and the majority, after lingering 

 along the shore a few weeks, pass north to their summer resorts, dur- 

 ing the first two weeks of May. Returning the last of August, while 

 resuming the winter dress, they remain more or less abundant until well 

 into November. In very mild winters a few remain during the season. 

 As is the case with the herring gull, many of the young of this spe- 

 cies do not proceed north, but remain along the Lake during the 



