488 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



cc. Back lirownish olive; lirown of chest and sides darker; yellow of al)domen more 

 restricted. (Colombia to Peru and Bolivia.) 



Myiobius xanthopygus villosus (extralimitalja 

 aa. Rump and entire und(>r parts yellowish buff; back light buffy olive. (Southeast- 

 ern Brazil.) Myiobius ridgwayi ('extralimital)& 



MYIOBIUS BARBATUS ATRICAUDUS ( Lawrence). 

 BLACK-TAILED MYIOBIUS. 



Adults (sexes alike). — Above plain greenish olive, the occiput with 

 a partially concealed patch of bright sulphur or canary yellow; 

 wings dull slaty brownish l)lack or dusky, with olive edgings; rump 

 primrose or pale sulphur yellow; upper tail-coverts and tail black; 

 sides of head and neck similar in color to upper parts but slightly 

 paler; malar region, chin, and throat pale buffy yellowish, passing 

 into light buffy olive on chest, the rest of under parts primrose or 

 pale straw yellow, the under tail-coverts mixed with pale olive or 

 grayish olive or wholly of that color; maxilla brownish black, man- 

 dible whitish (pale flesh color in life), with tip dusky; iris dark brown; 

 legs and feet dusky horn color in dried skins, plumbeous in life. 



Immature. — Similar to adults, but without any yellow on occiput. 



Adult male.— Length (skins), 108-127 (118); wing, 56-63 (58.3); 

 tail, 55-59.5 (56.9); exposed culmen, 10-11 (10.7); tarsus, 16-18 

 (16.7); middle toe, 9-9.5 (9.2).'^ 



a Myiobius villosus Sclater, Proc. Zool. Soc. Lend., 1860, 93, 465 (Rio Napo and Nan- 

 egal, e. Ecuador; coll. P. L. Sclater); Cat. Am. Birds, 1862, 226; Cat. Birds Brit.Mus., 

 xiv, 1888, 201 (Bogota and Frontino, Colombia; Rio Napo and Nanegal, Ecuador; 

 Tilotilo, Bolivia). — Myiobius xanthopygius (not Platyrhynchits xanthopygus Spix) 

 Taczanowski, Proc. Zool. Soc. Lond., 1874, 5.37 (Amable Maria, centr. Peru). 



This form agrees with M. sulphureipygius, as compared with M. xanthopygus, in 

 having the tail dull black, the brighter yellow crown-patch, and barred under tail- 

 coverts; but the olive of the back, etc., is darker and much browner, the brown of 

 chest and sides not only darker, but much more extended, only a small portion of the 

 abdomen being yellowish. The ground color of the under tail-coverts is light cinna- 

 mon-brown, not pale yellow. 



b (?) Myiobius barbatus (not Muscicapa barbata Gmelin) Koenigswald, Journ. fur 

 Orn., 1896, 359 (S. Paulo, s. Brazil); Ihering, Aves de S. Paulo, 1899, 201; Rev. Mus. 

 Paul., iv, 1900, 49 (descr. nest and eggs), 155 (Cantagallo and Novo Fribourgo, S. 

 Paulo). — Myiobius ridgxuayi Berlepsch, Auk, v, Oct., 1888, 457 (Petropolis, Province 

 of Rio de Janeiro, s. e. Brazil; coll. Count von Berlepsch). 



'^ Five specimens. 



