568 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Thryothorus brevlcaudiis Ridgway, 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!). 

 T[hryothorus'\ hrevicaudus Ridgway, Man. N. Am. Birds, 1887, 551. 

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

 Thryomanes hrevicaudus Ridgway, Proc. U. S. Nat. Mus., viii, Sept. 2, 1885, 354. — 



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



THRYOMANES INSULARIS (Lawrence). 

 SOCORRO WREN. 



Adults {sexes alike). — Above deep brownish ^vaj or hair brown, 

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

 ing very indistinct darker centers, the scapulars and interscapulars 

 with narrow obsolete dusky bars; rump with concealed roundish 

 spots of white, the feathers 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 butfy white, shading on sides and Hanks into pale grayish 

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

 spots, flecks, or bars of dusk}^; maxilla dusky brown with paler tomia; 

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

 dusky brownish. 



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

 ulate pale butfy brown and feathers of breast and sides narrowly 

 margined with dusky, producing a squamate effect. 



Adult male.—ljQngih (skin.s), 10(3-118.5 (114); wing, 46.5-1:9 (17.7); 

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

 (20); middle toe, 12-13 (12.6). « 



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

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



Socorro Island, Revillagigedo group, western Mexico. 

 Troglodytes insular is, 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. '> One specimen. 



