BIEDS OF NORTH AND MIDDLK AMERICA. 



133 



ff. Sides and flanks very faintly tinged witli yellowish olive; axillars, 

 under wing-coverta, and under tail-coverta very pale sulphur yellow 

 or nearly white. (Eastern North America, across continent in mid- 

 dle portion; south in winter to northern South America.) 



Vireosylva olivacea (p. 147) 

 CO. Exposed culmen not more than 10, decidedly shorter than middle toe with- 

 out claw; under parts olive-yellowish. (Eastern North America, south in 



winter to Ohiriqui. ) Vireosylva philadelphioa (p. 151 ) 



lib. Tenth primary obvious, longer than primary coverts. 

 c. Under parts of body dull whitish, the sides and flanks more olivaceous. 

 d. Pileum gray, back grayish olive. ( Vireosylva gilva. ) 



e. Paler above. (Eastern United States.) Vireosylva gilva gilva (p. 153) 



ee. Darker above, especially the pileum. 

 /. Smaller (adult male averaging wing 67.8, tail 50, exposed culmen 9.9; 

 adult female, wing 66.4, tail 48.5, exposed culmen, 9.8); sides and 

 flanks more strongly washed with olivaceous. (Western United 

 States, and British Columbia, south in winter to southern Mexico. ) 



Vireosylva gilva swainsonii (p. 155) 

 ff. Larger (adult male averaging wing 73, tail 52.5, exposed culmen 11.2; 

 adult female, wing 71.7, tail 50.3, exposed culmen 10.8); sides and 

 flanks more faintly tinged with olivaceous.' (Mountains of Chihua- 

 hua, northwestern Mexico.) Vireosylvia gilva brev^steri (p. 158) 



dd. Pileum brown, back olive-biown. {Vireosylva amawonota.) 

 e. Paler above, the pileum grayish sepia or deep hair brown, the back light 

 brownish olive. (Mountains of southeastern Mexico. ) 



Vireosylva amanronota amanronota (p. 158) 



A large series from Chapada, Matto Grosso, in the collection of the American Museum 

 of Natural History, is clearly a connecting series, nearly typical specimens of both 

 forms being represented, though a large majority are nearly typical chivi as to colora- 

 tion, but agreeing closely with agilii in larger size. The same may be said of speci- 

 mens from Bahia also, except that most of the specimens seen by me from the latter 

 locality are clearly V. agilis, as above characterized. It is a question, however, which 

 can only be settled by examination of the type in the Berlin Museum, whether Lich- 

 tenstein's name was based on a specimen representing the southern or northern type. 

 I have not seen specimens from any other locality so small as the two birds (one 

 from' the Vermejo River, the other from southern Brazil) brought to the National 

 Museum by the Page Expedition, their measurements comparing with those of a 

 series from Chapada, as follows: 



Locality. 



Middle 

 toe. 



MALES. 



One adult male from Vermejo River, Paraguay , 



One adult male from Corumba, Matto Grosso, Brazil 



Minimum of each, measurement in nine adult males from 



Chapada 



Average of nine adult males from Chapada , 



FEMALES. 



One adult female from, southeastern Brazil 



Minimum of each measurement in five adult females 



from Chapada 



Average of five adult females from Chapada , 



10 



10.4 



10 



10 

 10.2 



