BIRDS TYRANNINAE MYIARCHUS. 
177 
is needed to separate it from T. verticalis than its brown outer margin to the tail, nor from 
vou/erans 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 differences to distinguish them. 
Among a series of specimens otherwise quite similar, I find some difference 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. 
Catal. No. 
Locality. 
When collected. 
Whence obtained. 
Orig. No. 
8101 
4524 
8102 
8103 
8104 
S. F. Baird 
Dec. 28, 1855 
198 
do 
do 
MYIARCHUS, Cabanis. 
Myiarchus, Cabanis, Fauna Peruana 1844- '6, 152. — Bormeister, 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 Tyrannorum 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 II. crinilus. 
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. mexicanus. 
23 b 
