THE NATURAL HISTORY SURVEY. I75 



Genus GEOTHLYPIS Cabanis, 1827. 



Geothlypis trichas' brachidactyla (Swains.). Northern Yellow-throat. 



Sylvia trichas Nuttall, Man., I, 1832, 401, part. 



Oeothlifpis trichas Cabanis, in Nelson's Birds N. E. Illinois, Bull. 

 Essex Institute, Vol. VIII, 1876, 101. 



Geothlypis trichas A. O. U. Check-list, 1895, No. 681, part. 



Geothlypis trichas occidentalis A. O. U. Check-list, 1895, No. 681 u, 

 part. 



Geothlypis trichas trachidactyla Palmer (W), Auk, XVII, July, 1900, 

 221 (crit.). 



Trichas Irachidactyla SwAiNSON, Anim. in Menag., 1838, 295 ("North- 

 ern Provinces ot United States"). 



This Yellow-throat is a common summer resident, arriving 

 the last of April, and departing early in October. 



The form of this perplexing species which occurs within our 

 limits has been placed by writers under both trichas and trichas 

 occidentalis. While typical trichas is a distinctly eastern form 

 not being found west of southern Pennsylvania, excepting a single 

 accidental specimen taken in Knox County, Indiana, on May 5, 

 1885 (Ridgway*), typical trichas occidentalis, on the other hand, 

 is a distinctly western form and not found east of the western 

 portion of the Great Plains. I have examined quite a series of 

 specimens taken by various collectors within our limits. Xhese 

 show considerable variation, some approaching the eastern 

 trichas, and others the western trichas occidentalis. However, 

 the measurements and colors of all the specimens arie such as to 

 place them under trichas brachidactyla, a varietal name recog- 

 nized by both Palmerf and RidgwayJ for the northern form of 

 the Yellow-throat. 



Mr. Ridgway gives the following as the range of the North- 

 ern Yellow-throat :$ "Northeastern United States and south- 

 eastern British Provinces, from Newfoundland, southern Labra- 

 dor, Quebec, Nova Scotia, New Brunswick, the New England 

 States, Long Island, New York, and northern New Jersey, west- 

 ward to northern Ontario, Michigan, Wisconsin, Minnesota, and 

 eastern North Dakota, and southward through Mississippi Valley 

 to upland. districts of the Gulf States ( ?), and east-central Texas; 

 in winter, Bahamas, Cuba, Jamaica, Porto Rico (?), Swan 

 Island, and through eastern Mexico, and Yucatan, to Guatemala, 

 Nicaragua, and Costa Rica; whole United States east of the 

 Great Plains during migration." 



*Bull. U. S. Nat. Mus., No. 50, pt. li, 1902, 662. 

 tAuk, Vol. XVII, July, 1900, 221. 

 JBull. U. S. Nat. Mus., No. 50, pt. ii, 1902, 665. 



