BIRDS — TYRANNINAE — MYIAECHU8. 



177 



is needed to separate it from T. vertiealis than its brown outer margin to the tail, nor from 

 vouferans than its deeply forked tail and paler ash of the throat and olivaceous breast. 



Its resemblance to T. couchii (4003) is much closer. Both have a deep fork to the tail ; bright 

 gamboge yellow belly ; the bill of nearly the same size ; the shafts of the tail feathers white 

 beneath, &c. The tail is, however, more deeply forked, and much darker, nearly black ; the 

 feathers narrower ; the upper tail coverts darker ; the edgings on the wing yellowish, not 

 grayish white, &c. It is barely possible that the two may be the same, but at present I see 

 sufficient dififerences to distinguish them. 



Among a series of specimens otherwise quite similar, I find some difiTerence in the depth of 

 the fork of the tail, which in one is as much as .80 of an inch. The bills vary considerably, 

 both in size and proportions. All, however, agree well both with the T. melancholicus and T. 

 crudelis. Should two be distinguished, Swainson's name may be applied to the more northern 

 one. In my description I have taken the specimen from Vera Cruz as the type. 



List of specimens. 



MYIARCHUS, Cabanis. 



Myiarchus, Cabanis, Fauna Peruana 1844- '6, 152. — Burmeister, Thiere Brasiliens, II, Vogel, 1856, 469. 



Tarsus equal to or not longer than the middle toe, which is decidedly longer than the hinder one. Bill wider at base than 

 half the culmen. Tail broad, long, even, or slightly rounded, about equal to the wings, which scarcely reach the middle of 

 the tail ; the first primary shorter than the sixth. Head with elongated lanceolate distinct feathers. Above brownish olive, 

 throat ash, belly yellow. Tail and wing feathers varied with rufous. 



This genus is well marked among the American flycatchers, and constitutes what Bonaparte 

 called Ultimi Tyrannorwm sive Tyrannularum primae. The type is the Muscicapa ferox of 

 Gmelin, which, as identified by Cabanis and Burmeister as above, appears to resemble our 

 species very closely. The following analysis exhibits the peculiarities of the latter, including 

 a closely allied Mexican form : 



A. Inner web of tail feathers broadly rufous to the extreme tip. Bill broad ; its width 

 at base two-thirds the culmen. 



Colors darker. Brown stripe along the inside of shafts of tail feathers very 

 inconspicuous and narrow. Tarsus .84 of an inch M. crinitus. 



Colors paler. Brown stripe on inside of shafts of tail feathers very distinct, and on 

 the outer one broader than the outer web. Tarsus .95 of an inch.. ..if. cooperi. 



B. Inner web of tail feathers broadly rufous only to near the tip, which is brown. 



Colors pale. Tarsus .90 of an inch. Bill at base little more than one-half the 



culmen M. mexicanua. 



23 b 



