BIRDS OF NORTPI AND MIDDLE AMERICA. 3-17 



r. Crest bushy, partly yellow; general color, 

 including wings and tail, rufous. 



Pyrrhomyias (extniliniital)« 



rr. Crest pointed, wliolly brown or dusky; no 



rufous on upper parts (including wings 



and tail.) Mitrephanes (p. 496) 



qq. Not crested; tarsal envelope typically exas- 

 pidean; nostrils wholly exposed, circular, 

 nonoperculate, opening almost vertically. 

 Deltarhynchus (p. 502) 

 j)p. Bill larger, tlie exposed culinen equal to or longer 

 than middle toe with claw or else {Nuttallor- 

 nis) the latter decidedly longer than tarsus. 

 q. Tarsus decidedly shorter than middle toe with 

 claw; tail not more than two-thirds as long as 

 wing; longest primaries exceeding distal sec- 

 ondaries by much more than one-third the 

 total length of wing, the tenth (outermost) 

 longer than seventh; a conspicuous white silky 

 tuft on each side of rumj). .Nuttallornis (p. 504) 

 qq. Tarsus little, if any, shorter (usually longer) 

 than middle toe with claw; tail much more 

 than two-thirds as long as wing; longest pri- 

 maries exceeding distal secondaries by not 

 more (usually much less) than one-third the 

 total length of wing, the tenth (outermost) 

 shorter than seventh- (usually shorter than 

 sixth), 

 r. Tail less than eight-ninths as long as wing, 

 or else tenth (outermost) primary much 

 longer than fifth; tarsus less than one-fifth 

 as long as wing; tenth primary longer than 

 fifth; bill relatively narrower, with lateral 

 outlines straighter; rictal bristles shorter; 

 tail always emarginate. .Myiochanes (p. 508) 

 rr. Tail at least eight-ninths as long as wing 

 (usually more), tarsus more than onc-lifth 

 as long as wing; tenth (outermost) primary 

 not longer (usually shorter) than fifth; bill 

 relatively broader and more depressed, 

 with lateral outlines more convex; rictal 

 bristles longer; tail less deeply emarginate. 

 sometimes double-rounded or rounded. 

 s. Bill with lateral outlines more curved, the 

 tip more constricted; under parts with 

 neither yellow nor pale gray. 



Blacicus (p. 529) 



ss. Bill with lateral outlines straighter. the tip 



not distinctly if at all constricted; under 



parts pale gray anteriorly, light yellow 



posteriorly Myiarchus, part (p. 607 ) 



^Pyrrhomyias Cabanis and Heine, Mus. Hein., ii, 1859, 66. (Type, Tyrannula rieil- 

 lotioides Lafresnaye.) 



