270 BIRDS OF ILLINOIS. 



knobbed. Feet slender; tarsus rather longer than the middle toe; the hinder toe a little 

 longer than the outer lateral, which slightly exceeds the inner; the outer claw 

 reaching the base of the middle one. and half as long as its toe. Claws moderately curved. 

 Tertiaries and secondaries nearly equal; wing somewhat pointed, reaching not quite 

 to the middle of the tail. First quill a little shorter than the second and equal to the fifth ; 

 third longest. Tail rather long, moderately forked, and divaricated at the tip ; the feathers 

 rather narrow. Back streaked; rump and beneath immaculate. Young streaked beneath. 



"This genus differs from Zonotrichia principally in the smaller 

 size, and longer and forked instead of rounded tail. 



"Birds of the year of this genus are very difficult to distinguish, 

 even by size, except in monticola. The more immature birds are also 

 very closely related. In these the entire absence of streaks on a 

 plumbeous head point to atrigularis; the same character in a red- 

 dish cap, and a reddish upper mandible, to pusilla; a dusky loral 

 spot, with dark streaks, and generally a rufous shade on top of head, 

 to socialis. S. breweri, with a streaked head, lacks the dusky lore 

 and chestnut shade of feathers. S. pallida generally has a median 

 light stripe in the cap, and a dusky mandibular line." (Hist. N. 

 Am. B.) 



With a single exception, all the known species of this genus are 

 North American, though one of them (S. atrigularis) barely conies 

 within our borders in Arizona and southern California. The single 

 purely extralimital species is S. pinetorum SALVIN, of the Guatemalan 

 highlands. It is closely related to S. socialis, but is evidently distinct. 



Leaving out S. atrigularis and S. wortheni,* the species inhab- 

 iting the United States may be characterized as follows: 



COMMON CHABACTEKS. Back brownish, sharply streaked with black; rump plain 

 grayish; wings with two light bands; lower parts unstreaked, except in young. 

 A. Crown rufous in adults. 



a. Maxilla black, the mandible yellow; a dusky spot on the jugulum. 



1. S. montioola. Adult: Crown and outer webs of scapulars and tertials, bright 

 rufous ; two distinct white bands on the wing ; sides of head and neck ash-gray, 

 lighter on throat; a pale gray superciliary stripe, whitish anteriorly; a rufous 

 postocular stripe; a dusky spot in middle of the jugulum. 



6. Bill wholly black or reddish brown. 



2. S. pusilla. Bill wholly light reddish brown. Crown dull rufous; back dull 

 rufous, the feathers edged with grayish and streaked centrally with black; 

 outer edges of tertials pale grayish brown; sides of head pale ash-gray, with a 

 dull rufous streak behind the eye; wing with two indistinct bands. Young: 

 Crown and back dull grayish brown, without rufous; breast narrowly and in- 

 distinctly streaked with dusky. 



3. S. socialis. Bill wholly black in adults; dull reddish brown in young. Crown 

 bright rufous, becoming black anteriorly; a whitish superciliary stripe; a 

 blackish streak behind the eye; ear-coverts, sides of neck and rump, ash-gray. 

 Young: Crown and back brown. broadly streaked with black; breast and sides 

 thickly streaked with dusky. 



* Spizella wortheni KIDGW. Proc. U. 8. Nat Mus. vii. Aug. 22, 1884, 259. Silver City, 

 New Mexico. (Dedicated to Mr. Chas. K. Worthen. of Warsaw, Illinois.) 



