120 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



Breeding grounds protected in the following national reserva- 

 tions : In Alaska, Forrester Island ; in Michigan, Huron Island, and 

 Siskiwit Islands; in Wisconsin, Gravel Island and Green Bay; in 

 Canada, protected on Perce Rock. 



Winter range. — From the Great Lakes irregularly and the Gulf of 

 St. Lawrence rarely, southward to Bermuda, the West Indies (Cuba 

 and Jamaica) , and the Gulf of Mexico (Florida, Texas, and Yuca- 

 tan) ; on the Pacific coast from British Columbia (Puget Sound), 

 south to Mexico (Tres Marias Islands) ; in Europe from the British 

 Isles south to the Canary Islands and the Mediterranean ; and east 

 to the Black and Caspian Seas. 



Spring/ migration. — 'Dates of early arrival : Prince Edward Island, 

 April 1 ; Quebec, April 10 ; Montreal, April 13 ; Ottawa, March 13 ; 

 Wisconsin, Madison, March 2; Minnesota, Heron Lake, March 20; 

 Manitoba, Aweme, April 2 ; Alberta, Edmonton, May 1 ; Mackenzie, 

 Fort Simpson, May 14; Franklin, Bay of Merey, May 31, and Prince 

 of Wales Strait, June 7. Dates of late departure: Florida, Clear- 

 water Harbor, May 21 ; North Carolina, Pea Island, May 3 ; Mary- 

 land, Baltimore, May 28 ; Rhode Island, Providence, June 12 ; Massa- 

 chusetts, Woods Hole, July 4 (average June 11) ; Louisiana, New 

 Orleans, March 25; Missouri, St. Louis, May 28 (average April 15) ; 

 Illinois, Chicago, June 15 (average April 23). 



Fall migration. — Average dates of arrival : Massachusetts, Woods 

 Hole, August 21 ; New Jersey, Jersey City, September 21 ; Georgia, 

 Savannah, November ,3 ; Iowa, Keokuk, October 8. Average dates of 

 departure; Ungava, Fort Chimo, September 18; Labrador, Nakvak, 

 October; Montreal, November 5; Ontario, Ottawa, November 7; 

 Mackenzie, Fort Resolution, September 22; Manitoka, Killarney, 

 October 18. 



Egg dates. — Maine: Forty-eight records, May 4 to August 8; 

 twenty-four records, June 12 $p 30. Michigan : Twenty r five records, 

 May 21. to June 24; thirteen records, May 27 to June 10.- Gulf of St. 

 Lawrence : Nine records^ June 7 to 23. Great Britain : Nine records, 

 April 28 to May 26 ; five records, May 12 to 20; 



LAKUS THAYERI Brooks. 



THAYER'S GULL. 



HABITS. 



A new species has recently been described by Mr. W. Sprague 

 Brooks (1915), based on the discovery that certain gulls collected 

 by Mr. J. S. Warmbath, in Ellesmere Land in June, 1901, supposed 

 to be Kumlien's gulls, were in reality a distinct and undescribed 

 species. The discovery was made in attempting to identify a gull 



