TYRANNID.E — THE FLYCATCHERS. 333 



decidedly darker (except in var. hiwrencei) ; throat and jufnilum ashy-white ; 



rest of lower parts sidpliur-yollow. Ilah. Central and South Ameriea, and 



Jamaica. 



Pileuni sooty-brown, decidedly darker than the back ; wings and tail 

 entirely destitute of rntous edgings, except a faint tinge on outer webs 

 of inner secondaries and rectrices, towards the base. Tail faintly 

 rounded. Wing, 3.00; tail, 3.10; culmen, .80; tarsus, .65. Hah. 



Jamaica var. tristis} 



Pileum grayish-brown, not appreciably darker than the back; outer 

 webs of iinier sect)ndaries and primaries and rectrices faintly edged 

 with rufous. Wing, 2.80-3.40; tail, 2.85-3.45; culmen, .85 -.90; 

 tarsus, .75 -.80. Hab. Northern Mexico, from northern boundary, 

 south to Colima, Tehuantepec, Yucatan, and Salvador . \^v. lawrencei? 



Pileum sooty-blackish, decidedly and abruptly darker than the back. 

 Outer webs of wing-coverts, primaries, secondaries, and rectrices dis- 

 tinctly edged with rufous. Yellow beneath brighter than in lawrencei. 

 Wing, 3.20-3.30; tail, 3.15 -3..30; culmen, .80 -.85; tarsus, .75 -.80. 

 Hab. Central America from Panama to Guatemala (grading into var. 

 Zauvencei in Tehuantepec, and Orizaba) . . . var. nigricapillus? 



Pileum (leep black, al)ruptly different from the greenish-olive of the 

 back, and separated from it by a more ashy shade. Wings and tail 

 wholly destitute of rufous edgings. Yellow beneath brighter than in 

 var. nigricopillns. Wing, 3.20 ; tail, 3.20 ; culmen, .85 ; tarsus, .78. 

 Tail about even. Hah. Northwest South America, from Ecuador 

 northward (grading into nigricapillus on Isthmus of Panama). 



var. nigriceps.* 



ft 



1 Myiarchiis tristiA (Gosse), Coues. Myiobius tristis, Gosse, B. Jam. 167, pi. xli. Myiarchus t. 

 CouES, P. A. N. S. July, 1872, 80. 



2 Mifiarchics tristis, var. laicrencci (Giraud\ Baiud. Tyrannula Inwrauei, GiRAiTD, 16 sp. 

 Tex. B. pi. ii. Myiarchius 1. Baiud, Birds N. Am. 18.58, 181, pi. xl\-ii, f. 3. — Coues, P. A. N. S. 

 July, 1872, 74. 



Ohs. — The most typical speciineus are from Mazatlan and northward, across the northern 

 |)ortion of Mexico. On the eastern coast, specimens from Mir|idor and Or'-zaba ah i?ady strongly 

 incline toward var. nigricapillus. * 



* Myiarchus fristis, var. nigricapillus, Cabanis. ^''Myiarchus nigricapillus, Caban." Scl. 

 Cat. Am. B. 1862, 2^3, et Auct. M. lau-rniwi, CouEs, P. A. N. S. 1872, 74 (in part). 



Obs. — A very strongly differentiated form, but unquestionably grading into var. lawrencei on 

 the one hand, and var. nigriceps on the other. 



* Myiarchus tristis, var. nigriops, Sclatku. Myiarchus nigricrps, ScL. P. Z. S. 1860, 68, 

 295. — Coi'Es, P. A. N. S., July, 1872, 75. 



Obs. — The last three mces appear to be all reilucible to one speeies, as, taking the large series 

 of specimens before us (over .30 skins), we find it impossible to draw tlu> line In'tween them. 

 S|H'ciniens from Southern Mexico are referrible, with ecpial propriety, to lawrencei or to nigrica- 

 pillus, while skins from Panama of nigriceps are less typical than those from Ecuador. This 

 case of gradually increasing melanistic tendency as we proceed southward affords an exact pamllel 

 to that 01 Virccsylvia gilvus and V. josepha^, Sayomis nigricans and S. aquaficus, and many 

 other cases. 



