TERETRISTIS. 



237 



B. Wings rounded ; the 1st quill shorter than in the preceding 

 section, always less than the 5th. 

 1. Bill much depressed, and widened at base. Culmen 

 and commissure quite straight to near the tip. 



a. Bill attenuated towards the end ; lateral outlines 



straight or concave. Tail decidedly longer 

 than the wings. Second quill as long as 6th. 

 Rictal bristles reaching nearly to tip of bill, 

 which from gape is rather less than the 

 length of skull. Tail considerably grad- 

 uated (.50), the feathers soft, broad; 

 the outer web of outer feather wide, 

 nearly even, and about one-third the 

 width of inner. A rufous patch on 



vertex Myioborus. 



Rictal bristles reaching a little beyond mid- 

 dle of bill, which is elongated, and from 

 gape about equal to length of skull. 

 Tail moderately rounded, the feathers 

 firm ; the outer web of outer feather 

 not more than one-fourth the width of 

 inner. A yellow stripe on vertex . Eathhjpis. 



b. Bill broad towards the end ; lateral outlines ob- 



tuse, like Todirostrmn. Tail very little longer 

 than the wings. Second quill much shorter 

 than 6th. 



Rictal bristles extending just beyond nos- 

 trils. Tail graduated, the feathers nar- 

 row, pointed. Outer webs narrow . Myiothlypis. 

 2. Bill pointed, depressed, and more or less wide at base, 

 but deep, and the culmen gently curved from the base. 



a. Tail nearly even, the feathers narrow, about equal 



to or very little longer than the lengthened 

 wings (1st quill about equal to the 7th). Bill 

 thickened, and broad at base. Rictal bristles 

 lengthened. Tarsi short. Vertex with two 

 black stripes inclosing a median one of a yel- 

 low, orange, or ashy color .... Basileuterus. 



b. Tail decidedly longer than the abbreviated wings 



(1st quill not longer than 9th), much grad- 

 uated, the feathers narrow. Bill rather nar- 

 row, scantily bristled. Tarsi long. Top of the 

 head chestnut ...... Idiot es. 



c. Tail about equal to the lengthened wings (1st quill 



about equal to the 6th), nearly even, the 

 feathers broad. Bill very small, and narrow ; 

 rictus well bristled ; prevailing color red. . Ergaticus. 



