172 THE CHICAGO ACADEMY OF SCIENCES. 



that of S. n. noveboracensis, the feathers entirely dusky (except 

 the buffy tip), instead of olive with a subterminal bar of dusky." 

 He also says that he is not sure that the differences between the 

 young of the two forms, as stated above, are constant as he had 

 but one specimen of each form to examine. Mr. Ridgway also 

 states that the "Mississippi Valley specimens average smaller than 

 those from the Rocky Mountains and westward, and are really 

 intermediate in size between S. n. notabilis and S\ n. novebora- 

 censis." 



The range of this Water-thrush may be given as western 

 North America, and passing more or less commonly during its 

 migrations through the Mississippi Valley as far eastward as In- 

 diana, and much more rarely through the states of the Atlantic 

 coast to the Bahamas, Cuba, and through Mexico and Central 

 America to northern South America. 

 Seiurus motacilla (Vieillot). Louisiana Water-thrush. 



Turdus motacilla VIEILLOT, Ois. Amer. Sept., II, 1807, 9, pi. 65. 



Seiurus ludovicianus BONAPARTE, Geog. and Comp. List, 1838, 21. 



Seiurus motacilla BONAPARTE, Consp. Av., I, 1850, 306. 



Siurus motacilla COUES, Bull. Nutt. Orn. Club, II, 1877, 33. 



Popular synonyms: LARGE-BILLED WATER-THRUSH. WATER WAGTAIL. 

 WAGTAIL. 



The Louisiana Water-thrush is a rare summer resident, arriv- 

 ing about the last of April, and departing about the first of Sep- 

 tember. In 1876 Mr. E. W. Nelson recorded it as a "not uncom- 

 mon summer resident." 



The range of this species includes the United States, east of 

 the Great Plains and from southern New England and southern 

 Michigan southward in winter to the West Indies and through 

 Mexico and Central America to Panama. It is a casual visitor 

 further north than the above range. It breeds quite throughout 

 its range within the United States. 



Genus OPORORNIS Baird, 1858. 



Oporornis formosa (Wilson). Kentucky Warbler. 



Sylvia formosa WILSON, Amer. Orn., Ill, 1811, 85, pi. 25, fig. 3. 

 Oporornis formosus BAIRD, Rep. Pacific R. R. Surv., IX, 1858, 247. 

 Geothlypis formosa RIDGWAY, Proc. U. S. Nat. Mus., VIII, 1885, 354. 



At the present time the Kentucky Warbler is certainly 

 a very rare summer visitant from southern Illinois." In 

 his report published in 1876, Mr. E. W. Nelson says* : "A very 

 rare summer visitant from southern Illinois." The only other 

 records of its appearance in our vicinity are the following. Dr. 

 flocks along the Lake shore and on bare prairies during the migra- 



k Birds of Northeastern Illinois, Bull, of the Essex Institute, Vol. VIII, 1876, 101. 



