103 



dense willow thicket bordering Mazon Creek, about sixty miles south 

 of Chicago. Upon ray approach the birds showed great anxiety, utter- 

 ing a short complaining cry, and coming within a few feet of me. 

 That they had young in the vicinity I was sure, but owing to the char- 

 acter of the covert they were not found. Specimens of this species 

 may invariably as far as my experience goes be separated from 

 those of V. gilvns by the greater intensity of yellow on the former, as 

 well as by the quill characters. 



72. V. gilvus Cass. WARBLING VUIEO. A common summer res- 

 ident. Arrives May 8th to loth; departs in September. 



73. V. solitarius Bd. BLUE-HEADED VIKEO. An abundant mi- 

 grant; May 5th to 25th, and the last of September and first of Octo- 

 ber. Found everywhere in the woods and thickets. 



74. V. flavifrons Bd. YELLOW-THROATED VIREO. A common 

 migrant and not uncommon summer resident. May 8th to 24th, and 

 September 10th to October 15th. 



75. V. noveboracensis Bonap. WHITE-EYED VIREO. Summer 

 resident. Rather rare. Arrives the middle of May and departs the 

 first of October. Very common in Southern Illinois. 



76. V. belli And. BELL'S VIRKO. A single specimen, obtained 

 near Chicago, June 23, 1875, is the only instance I have recorded of 

 its occurrence in this vicinity. It is a common summer resident on 

 the more southern prairies of the state. 



Family AMPELIDJE. 

 Genus Ampeiis Linn. 



77. A. garrulus Linn. BOHEMIAN WAXWING. An irregular but 

 occasionally abundant winter resident, especially along 'the lake. Ar- 

 rives in December and sometimes remains until April. The winter 

 of 1875-G they were unusually numerous. In a letter dated March 16, 

 1870, Mr. Charles Douglas, of Waukegau, describes an "immense" 

 flock of these birds which he observed the day previous, upon the 

 lake shore near that town. The birds were feeding upon the juniper 

 berries found there, and covered, according to Mr. Douglas's estima- 

 tion, an area_ at least ten rods square. While feeding, those in the 

 rear were continually flying and alighting hi advance, thus keeping 

 the flock moving so that it was difficult to overtake them. A few 

 days later the flock separated into numerous smaller ones and soon 

 departed for the north. 



78. A. cedrorum. Scl. CEDAR BIND. Common summer resident. 

 Arrives the last of February, breeds from the first of June until the 

 middle of July; leave late in autumn. 



