72 BIRDS OF ILLINOIS. 



FAMILY SYLVIID^J. THE WARBLERS. 



CHAKACTEBS. There is very little by which to distinguish the birds of this Family from 

 the Turdidae, beyond the very much smaller size and the unspotted plumage of the young. 

 Of the so-called subfamilies here recognized, the Polioptilina; are without much question 

 out of place, though it is very uncertain where they do belong. For the convenience of 

 the student, however, we place them here in accordance with the arrangement adopted by 

 the American Ornithologists' Union. 



American Ornithologists' Union. 

 The so-called subfamilies may be distinguished as follows: 



a. 1 Wings longer than the nearly even or emarginate tail. Anterior tarsal 

 envelope continuous for the greater part of its extent. No white on tall. 



6. 1 Nostrils exposed. Scutellae distinct on inner ^ide of tarsus Sylviinae 



ft. 1 Nostrils concealed by feathers. Tarsal envelope without appreciable 



scutellse Regulinae 



a. 1 Wings not longer than the graduated tail. Anterior tarsal envelope dis- 

 tinctly scutellate. Tail with white terminal spots and edgings Polioptilinae 



SUBFAMILY POLIOPTILINAE. THE GNATCATCHERS. 

 GENUS POLIOPTILA SCLATER. 



Polioptila SCLATEB Pr. ZooL Soc. 1855, 11. Type, Motacilla ccerulea LINN. 

 CHAR. Bill slender, attenuated, but depressed at the base; nearly as long as the head, 

 distinctly notched at the tip, and provided with moderate rictal bristles. Nostrils rather 

 elongated, not concealed, but anterior to the frontal feathers. Tarsi longer than the 

 middle toe, distinctly scutellate; the toes small, the hinder one scarcely longer than the 

 lateral; its claw scarcely longer than the middle. Outer lateral toe longer than the inner. 

 First primary about one-third the longest; second equal to the seventh. Tail a little 

 longer than the wings, moderately graduated; the feathers rounded. Nest felted and 

 covered with moss or lichens. Eggs greenish white, spotted with purplish brown. 



"The species all lead-color above ; white beneath, and to a greater 

 or less extent on the exterior of the tail, the rest of which is black. 

 Very diminutive in size (but little over four inches long)." (Hist. 

 N. Am. B.) 



