BLACK-THEOATED BLUE WAEBLEB. 59 



Sombrero Key light was struck hy birds on eleven nights. Thirteen 

 species of warblers were noted among the birds killed, but none of 

 these were CBerulescens. The latter species, however, was taken in 

 four out of the next five flights. The evidence was just as strong the 

 next season. This species was not taken during the first six flights of 

 March and early April, but after April 14, when the bird was first 

 observed among those striking the light, it was included in every large 

 flight of the ensuing month. This seems to show that the species does 

 not normally begin its migration much before the middle of April, 

 and furthermore that some individuals may make the journey from 

 Cuba to the southern Allegheny Mountains at a single flight. 



The latest date on which a north-bound migrant was noted at Raleigh, 

 N. C, in the eleven years from 1890 to 1900 was May 16, and the 

 average of the dates on which the latest migrant passed was May 11. 

 There is an apparent discrepancy between these Raleigh dates and the 

 dates on which the birds are I'ecorded as passing the southern Florida 

 lighthouses. As previously shown, the journey from the lighthouses 

 to North Carolina should occupy a month, yet black-throated blue war- 

 blers struck the lights in May for five consecutive years, and in 1889 

 as late as May 29. On May 8, 1888, 41 birds struck the lights and on 

 Ma}^ 12, 18; 17 birds struck one of the lighthouses near St. Augus- 

 tine May 14, 1884, and dead birds were picked up at Alligator Reef 

 lighthouse May 21, 1885, and May 11, 1888. North of Raleigh the 

 average date of arrival at Frenchcreek, W. Va., is April 29; Wash- 

 ington, D. C, and Kenovo, Pa., May 3; Philadelphia and southeastern 

 New York, May 6; northeastern New York, May 9; central Massa- 

 chusetts, May 8; Boston, May 10; St. Johnsbury, Vt., May 9; 

 southern Maine, May 14; Quebec, May 11; central New Brunswick, 

 May 16. 



In southern Louisiana and southern Mississippi the black-throated 

 blue warbler is almost unknown. In eight years' collecting in this 

 region three good ornithologists saw but two individuals of the spe- 

 cies. In northwestern Mississippi, however, at Shell Mound, three 

 birds were seen on April 7, 1892, and the species was common the next 

 day. At New Orleans spring migrants were recorded on March 22, 

 1894, and March 26, 1897. These dates are in advance of those of the 

 ordinary migration to southern Florida, and undoubtedly represent a 

 movement directly across the Gulf of Mexico. 



Migration west of the AUeghenies corresponds almost exactly in 

 time with that at corresponding latitudes along the Atlantic slope, as 

 evidenced by the following records of average date of arrival : Brook- 

 ville, Ind, April 30; Waterloo, Ind., May 5; northern Ohio, Chicago, 

 and southern Michigan, May 7; Milwaukee, Wis., May 9; southern 

 Ontario, May 8; Parry Sound district, Ontario, May 10; Ottawa, 

 May 11. 



