TYUANNID.'E — THE FJA'CATCIIEUS. 329 



Tyrannus melancholicus, var. couchi, Baird. 



COUCH'S KINOBIBD. 



Tyrannus eouchi, I)aiui>, Birds N. Am. 1858, 17.'>, \<\. xlix, f. 1.— Sui.. Catal. Am. B. 

 18G2, 235. 



Sr. Chah. ]?ill long a.s tlio lioail. Feet sloiit. Five outer priinarie.s al)niptly attenuated 

 at (lie end ; tlie tliinl anil lourtli loiii,'est ; tlie (ir.^t a little lonjrer tlian tlii' si.xtli. Tail 

 consiilerahly I'orked (depth of fork about .;!l) of an ineli, or more;. Head, neek, and 

 jugulum l)]uisli-a.sliy, beeoniing nearlj' white on the throat, and shaded with yellow on 

 the breast. Ile.st of lower parts }i;atnbo<ro-yellow. Rest of ujiper parts olive-green, 

 tinged with ash anteriorly. Tail and primaries grayish-brown, the tail not the darker. 

 Wing-coverts ])nssing externally into pale, the tertials edged witii almost white. Crown 

 with a concealed patch of bright orange-red. Length, 0.00; wing, 'i.tK) ; tail, 4."0. 



Hah Middle America (both coasts), from southern border of Uijited States, south to 

 Guatemala; Tucson, Arizona (Bkndiuk). 



All specimens of T. mclonrholicns from regions north of Guatemala are 

 reforrible to var. von rid ; all I'mni Costa liica southward, to mclanchiilinis. 



It is only Ity comparing specimens from near the extreme nortlierii and 

 soutlieru limits of tlie range of the species, that differences are readily dis- 

 ceriiil)le ; and hetween tliese two extremes there is so gradual a transition that 

 it is iinpo.ssil)le to draw a line; se])arating two well-marived varieties, so that it 

 is necessary to assume an arl)itrai'y ge()grai)liical lino, and determine speci- 

 mens from the middle regions by their i)osition, wlietlier to the nortli or 

 south of the line establislied. Si)ecimens from Ikienos Ayres, the Parana, 

 and IJrazil, to Peru and New (iranada, are identical. Costa Ilica specimens 

 (7'. scttnqm, LicllT.) have the dark tail of var. Diclunclioiicua and white throat 

 of eouchi. 



Genus MYIARCHUS, Cabanis. 



Myinrcktm, Caiianis, Fainm Ti'mann, 1844-46, 152. — Burmeistkh, Thiiu-e Brasilicns, 

 II, Viigcl, 1850, 4ti!). 



Gen. Char. Tarsus equal to or not longer than the middle toe, wliich is decidedly 

 longer than the hinder one. Bill wider at bn.<?e than h.alf the culmen. Tail broad, long, 

 even, or slightly rounded, about equal to the wings, which scarcely reach the niiildle of the 

 tail; the fust primary shorter than the sixth. H(;ad with elongated lanceolate distinct 

 feathers. Above brownish-olive, throat ash, belly yellow. Tail and wing feathers varied 

 with rufous. 



This geinis is well marked among the American "nyratohers, and consti- 

 tutes what r>onaiiartt! (tailed ITItimi Tifrtinnovnm sire 7\i/minni/((ri(m prima: 

 Tlie type is the Afimrirnjin f('ro.v of Gmelin, (M. ff/mniinliis,) wliieh, as identi- 

 fied by Cabanis and Ihirmeister as above, ap])ears to resemble our s])ecies 

 very closely. 



For an elaborate discussion of the variiuis forms of this e.xccedingly dith- 



voi,. u. 42 



