BIRDS OF NOKTH ANB MIDDLE AMEEICA. 633 



67-71 (69); tail, 56-58 (57); exposed culnien, 15-18 (16.7); tarsus, 

 23-24 (23.5); middle toe, 16-16.5 (16. 2). « 



Young. — Similar in color of upper parts to adults, but darker and 

 duller, especially on pileum; superciliary stripe narrower, less sharply 

 defined, brownish buffy; under parts dull grayish white medially, the 

 chest sparsely flecked with dusky; lateral under parts dull grayish 

 brown, tinged with rusty brown or chestnut; under tail-coverts pale 

 rusty, barred with dusky. 



Highlands of western Guatemala (VolcandeFuego; Duenas; Savana 

 Grande; San Diego; Escuintla, Retalhuleu; Coban); Honduras? 



Thriothorus rufalbus Lafresnaye, Eev. Zool., viii, 1845, 337 ("Mexico;" type 

 in coll. Boston Soc. Nat. Hist.; see Ridgway, Proc. Bost. Soc. N. H., xxiii, 

 1888, 386). 



Tlwyothorus rufalbus Bonaparte, Consp. Av., i, 1850, 221. — Sclater and Salvin, 

 Ibis, 1859, 8 (Duenas, Guatemala). 



[Thryophilus] nifalbus Sclater and Salvin, Nom. Av. Neotr., 1873, 6, part 

 (Guatemala). 



Thryophilus rufalbus Salvin and Godman, Biol. Centr.-Ani., Aves, i, 1880, 82, 

 part (Volcan de Fuego, Duenas, Savana Grande, San Diego, Escuintla, Retal- 

 huleu, and Coban, Guatemala). — Sharpe, Cat. Birds Brit. Mus., vi, 1881, 

 212, part (Guatemala).— Salvin, Cat. Strickland Coll., 1882, 77 (Guate- 

 mala). — Ridgway, Proc. Bost. Soc. N. H., xxiii, 1888, 386 (remarks on type 

 specimen). 



Tlliryophilusl rufalbus rufalbus Hellmay'r, Verb. k. k. zool.-bot. Gesellsch. 

 Wien, 1901, 767, in text. 



T[roglodytes'] rufalbus Gray, Gen. Birds, i, 1847, 158. 



IThryothorus'] poliopleura Baied, Review Am. Birds, Aug., 1864, 122 (diagnosis). 



Thryophilus rufalbus, yht. poliopleura Baiuti, Review Am. Birds, Aug., 1864, 128 

 (Savana Grande, Guatemala; coll. U. S. Nat. Mus.). 



[Troglodytes'] poKopleurus G'RAY, Hand-list, i, 1869, 190, no. 2599. 



Thryophilus rufalbus poliopleura Goodu, Bull. U. S. Nat. Mus., no. 20, 1883, 345. 



THRYOPHILUS RUFALBUS CASTANONOTUS Ridgway. 

 CHESTiror-BACKED WREN. 



Similar to T. r. rufalitis, but black bars on tail much broader, usually 

 more than half as wide as the chestnut interspaces on middle rectrices, 

 sometimes even wider; dusky bars on secondaries broader and darker 

 in color; dusky streaks on sides of head broader; sides and flanks 

 tawny -brown instead of grayish. 



Adult male.— Ijength {skma), 130-162 (143.8); wing, 66-74 (70.1); 

 tail, 48-57.6 (62.1); exposed culmen, 18-21 (19.1); tarsus, 23.5-26.6 

 (24.3); middle toe, 15.5-17 (16).* 



Adult female.— Length (skins), 129.5-148 (140.6); wing, 64-76 



a Three specimens, including two of Lafresnaye's types; none of them with sex 

 determined. 



i Ten specimens. 



