04 NORTH AMERICAN WARBLERS. 



mon, in Haiti and Porto Rico, which latter island marks the limit of 

 the eastern extension of the species. It also winters in southern 

 Florida. To the south it has been taken on Grand Cayman, Little 

 Cayman," Cayman Brack," the Swan Islands,* Cozumel," Ruatan,'' and 

 Old Providence,^ but has not as yet been noted on the mainland of 

 Honduras or Nicaragua. Two occurrences on the mainland of Yuca- 

 tan/ are recorded, and one of the parties of the Biological Survey 

 found the species not uncommon on Cozumel Island, more common 

 on Mujeres Island, and very common during March and April, 1901, 

 on the mainland of Yucatan, at La Vega. 



Spring migration. — It is impossible to separate the records of occur- 

 rence of the two forms of this species during spring migration in the 

 Gulf States, with the exception of those made at the lighthouses of 

 southern Florida. Here the earliest individuals of the western form 

 to strike the lights were noted on April 4, 1886, March 23, 1887, 

 March 10 and 11, 1888, and March 3, 11, 23, and 21, 1889. Palm war- 

 blers were among the most numerous in the clouds of small birds that 

 swarmed around the lights on the night of March 3, 1889. They were 

 reported on the same night from both Sombrero Key and Fowey 

 Rocks — one of the few instances in which a species has been so reported 

 from the two points. The next certain records of the occurrence of 

 the western form were made at St. Louis, where it was noted April 13, 



1883, April 18, 1884, April 13, 1887, and April 17, 1888. These dates 

 correspond closely with those on which the species has been observed 

 in central Indiana — April 17 to 21. Records of average date of 

 arrival farther north are: Chicago, April 25; southern Michigan, May 

 1; southern Ontario, May 2; southern Wisconsin, April 30; Hillsboro, 

 Iowa, April 22; Lanesboro, Minn., April 30; Elk River,, Minn., May 

 3; Aweme, Manitoba, May 7. A specimen was taken at Fort Chip- 

 pewyan, Athabasca, May 23,. 1901. The fact that the bulk of the 

 western form winter farther south than does hypochrysea of the East 

 is reflected by the lateness of spring migration in the Mississippi Val- 

 ley, as compared with the earliness of the northward movement on 

 the Atlantic coast. By the time palmarum has arrived at St. Louis 

 hypochrysea has reached New England. The last palm warblers to 

 pass northward in spring have been noted at St. Louis on May 9, 



1884, May 12, 1885, and May 10, 1887, and in central Indiana about 

 the middle of May. These dates probably mark the normal passage 



o Cory, Auk, VI, p. 31, 1889. 

 ftRidgway, Proc. U. S. Nat. Mus., X, p. 575, 1888. 

 cRidpway, Proc. U. S. Nat. Mus., VIII, p. 564, 1885. 

 '' Salvin, Ibis, p. 251, 1888. 

 f Cory, Auk, IV, p. 180, 1887. 



/Boucard, P. Z. S., p. 441, 1883. Stone, Proc. Acad, Nat, Sci., Phila., p. 211, 

 1890, 



