568 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Thryothorus brevicaudus Kidgway, Proc. U. S. Nat. Mus., viii, Sept. 2, 1885, 354. — 



American Ornithologists' Union, Check List, 1886, no. 720.— Bryant, Bull. 



Cal. Acad. Sci., no. 6, 1877; ii, 1887, 312 (habits). — Anthony, Condor, iii, 



1901, 73 (said to be extinct!). 

 Tlhryothorus} brevicaudus Eidgway, Man. N. Am. Birds, 1887, 551. 

 Thryothorus brevicauda Sharpe, Cat. Birds Brit. Mus., vi, 1881, 227. 

 Thryomanes brevicaudus Ridqway, Proc. U. S. Nat. Mus., viii, Sept. 2, 1885, 354. — 



Oberholser, Proc. IT. S. Nat. Mus., xxi, 1898, 448 (monogr.). 



THRYOMANES INSULARIS (Lawrence). 

 SOCORRO WREN. 



Adults (sexes alike). — Above deep brownish gray or hair brown, 

 more decidedly brownish on rump, the feathers of pileum show- 

 ing very indistinct darker centers, the scapulars and interscapulars 

 with narrow obsoletp dusky bars; rump with concealed roundish 

 spots of white, the f leathers dark slate color basally; upper tail- 

 coverts narrowly, sometimes very distinctly, barred with dusky; 

 middle rectrices grayish brown or brownish gray, barred with dusky, 

 the remaining rectrices similar on outer webs, but lateral rectrices 

 with paler bars broader and dull whitish; inner webs of rectrices 

 (except middle pair) dusky brownish gray, showing very indistinct 

 or obsolete narrow dusky bars, and narrowly edged with white, the 

 exterior rectrix with one or more dull whitish bars or other shaped 

 markings near tip; wings brownish gray narrowly barred with dusky, 

 the five or six outermost primaries edged or serrated with whitish; a 

 narrow and inconspicuous superciliary stripe and a narrow orbital 

 ring dull white or pale brownish buffy, the lores similar but tinged 

 with grayish; a broad postocular stripe of grayish brown or brownish 

 gray, occupying upper portion of auricular region; rest of auricular 

 region dull whitish indistinctly streaked with dusky ; under parts dull 

 white, or buffy white, shading on sides and flanks into pale grayish 

 brown, the latter more brownish; under tail-coverts with a few small 

 spots, flecks, or bars of dusk3'; maxilla dusky brown with paler tomia; 

 mandible pale brownish, more or less dusky terminally; legs and feet 

 dusky brownish. 



Young. — Similar to adults, but flanks and under tail-coverts immac- 

 ulate pale buffy brown and feathers of breast and sides narrowly 

 margined with dusky, producing a squamate effect. 



Adult male.— Length (skins), 106-118.5 (114); wing, 46.5-49 (47.7); 

 tail, 40-46.5 (43.8); exposed culmen, 14-15.5 (15.1); tarsus, 19.5-21 

 (20); middle toe, 12-13 (12.6). « 



Adult female. — Length (skin), 116; wing, 48; tail, 45; exposed cul- 

 men, 15.5; tarsus, 21; middle toe, 13.* 



Socorro Island, Eevillagigedo group, western Mexico. 

 Troglodytes insularis, Baird, MS., Lawrence, Ann. Lye. Nat. Hist. N. Y., x, 

 Feb., 1871, 3 (Socorro I., Revillagigedo group, n. w. Mexico; coll. U. S. 



» Nine specimens. b One specimen. 



