688 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Adult maZ6^— Length (skins), 131-143 (135.8); wing, 55-62 (58.2); 

 tail, 56-67 (62.2); exposed culmen, 10-12 (11.5); tarsus, 20-23 (21.6); 

 middle toe, 13-16 (14.6).' 



Adult female.— hQngt\i (skins), 127-135 (132.7); wing, 51-55 (54.5); 

 tail, 55-60 (58.2); exposed culmen, 11-12 (11.5); tarsus, 19-21 (20.8); 

 middle toe, 13-15 (14.2).^ 



Northern, western, and central Mexico; south to States of Morelos 

 (Yautepec, January) and Michoacan (Querendaro, August), north to 

 State of Sinaloa (vicinity of Mazatlan) and to the lower Rio Grande 

 Valley in Texas (Brownsville). 



Geothlypis poliocephala Baird, Review Am. Birds, April, 1865, 225 (Mazatlan, 

 Sinaloa, w. Mexico; coll. U. S. Nat. Mus. ). — Salvin, Ibis, 1872, 149, part 

 (monogr.) . — Ridgway, in Baird, Brewer, and Ridgway's Hist. N. Am. Birds, 

 i, 1874, 296 (Mazatlan).— Lawrence, Mem. Best. Soc. N. H., ii, 1874, 269 

 (Mazatlan). — Salvin and Godman, Biol. Centr.-Am., Aves, i, 1881, 154, pi. 9, 

 fig. 3 (Mazatlan).— Sharpe, Cat. Birds Brit. Mus., x, 1885, 359, part (Presidio, 

 near Mazatlan). 



[Geothlypis] poliocephala Sclater and Salvin, Nom. A v. Neotr., 1873, 10, part. 



G\_eothlypiii] poliocephala Ridgwav, Man. N. Am. Birds, 1887, 526. 



[Trichaii] poliocephala Gray, Hand-list, i, 1869, 242, no. 3507. 



\_Geothlypls poliocephala'] ex. poliocephala Ridgway, Am. Jour. Sci., iv, Dec, 

 1872, 459. 



Geothlypis poliocephala var. poliocephala Ridgway, Am. Journ. Sci., iv, Dec, 

 1872, 459. 



[Geothlypis poliocepliala'] var. poliocephala Ridgway, in Baird, Brewer, and Ridg- 

 way's Hist. N. Am. Birds, i, 1874, 296. 



[Geothlypis poliocephala] a. G. poliocephala Sharpe, Cat. Birds Brit. Mus., x, 



.1885, 360, over list of specimens. 

 Geothlypis poliocephala palpebralis (not G. palpebralis Ridgway) Allen, Auk, viii, 

 1891, 316 (Brownsville, Texas). 



^ Ten specimens. 

 ■■'Six specimens. 



Specimens from Mexico comjiare in average measurements with those from 

 Brownsville, Texas, as follows: 



The series from Mexico is a very unsatisfactory one, but such as it is it seems to 

 invalidate the claims of G. p. ralpld as a recognizal^Ie form. 



