132 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



g. Sides and flanks more extensively and uniformly olive-yellow; under 

 tail-coverts deeper sulphur yellow; no distinct, if any, dusky post- 

 ocular streak. 

 h. Superciliary stripe brownish gray, indistinct; pileum without dis- 

 tinct, if any, dusky lateral line. ( Vireosylva flavoviridw. ) 

 i. Smaller (adult male averaging wing 78.1, tail 51.6, tarsus 18.4); 

 superciliary stripe more distinct and dusky lateral line of pileum 

 usually obvious. (Northern Mexico to Isthmus of Panama. ) 

 Vireosylva flavoviridis flavoviridis (p. 144) 

 ii. Larger (adult male averaging wing 83, tail 59.2, tarsus 20.1); 

 superciliary stripe less distinct and dusky lateral line of pileum 

 usually obsolete. (Tres Marias Islands, western Mexico. ) 



Vireosylva flavoviridis forreri (p. 146) 



hh. Supercilianry stripe grayish white, distinct; pileum with a very 



distinct lateral line of dusky. (San Miguel Island, Gulf of 



Panama.) Vireosylva insulaims (p. 147) 



gg. Sides and flanks less extensively and uniformly olive-yellow; under 

 tail-coverts paler sulphur yellow; a distinct dusky postooular 

 streak. ( Vireosylva chwi. ) 

 h. Larger (adult male averaging wing 76, tail 52.9, exposed culm en 

 14, tarsus 176; adult female, wing 68.3, tail 47.4, exposed culmen 

 13.3, tarsus 17); back, etc., much brighter olive-green, pileum 

 much purer gray, sides and flanks much more strongly washed 

 with olive-yellow, and under tail-coverts deeper sulphur or prim- 

 rose yellow. (Northern South America, south to Bahia and 



central Brazil.) Vireosylva ohivi agilis (extralimital)'^ 



hh. Smaller (adult male with wing 63, tail 45.5, exposed culmen 12, 

 tarsus 18; adult female, wing 62, tail 44, exposed culmen 11.5, 

 tarsus 16); back, etc., much duller olive-green; gray of pileum 

 duller; sides and flanks less strongly washed with olive-yellow, 

 and under tail-coverts paler yellowish. (Paraguay, Argen- 

 tina, and southern Brazil. ) . .Vireosylva ohivi ohivi (extralimital) 6 



iJ'L[_amus] agilis Lichtenstein, Verz. Doubl., 1823, no. 536 (Bahia, e. Brazil; coll. 

 Berlin Mus. ). — Phyllomanes agilis Burmeister, Syst. Ueb. Th. Bras., Aves, ii, 1856, 108 

 (part, at least). — VireosyMa agilis Sclater, Proc. Zool. Soc. Lond., 1860, 64 (Palla- 

 tanga, w. Ecuador), 273 (Babahoyo, w. Ecuador); Cat. Am. Birds, 1862,44 (Bogota, 

 Colombia; Pard, lower Amazon; Pallatanga). — Baird, Review Am. Birds, 1866, 338 

 (Buenos Aires; Ecuador; Guatemala?; Brazil; Trinidad). — Pelzeln, Orn. Bras., 1868, 

 73. — V[ireosylvia'] flavoviridis var. agilis Baird, Brewer, and Bidgway, Hist. N. Am. 

 Birds, i, 1874, 359. — Vireo bariramii (not of Audubon) Swainson, Fauna Bor.-Am., 

 ii, 1831, 235. — Vireosylvia virescens (not Vireosylvia virescens Vieillot) Cassin, Proc. Ac. 

 Nat. Sci. Phila., 1851, 151 (Trinidad); Sclater, Proc. Zool. Soc. Lond., 1855,151 

 (Bogota). — Vireo {Vireosylva) lirescens Baird, Hep. Pacific E. E. Surv., ix, 1858, p. 

 "xxxxv" ( = xxxv). — Vireo virescens (not of Vieillot) Baird, Rep. Pacific R. R. 

 Surv., ix, 1858, 333, excl. syn. part (Brazil). — Vireo chivi (not Sylvia chici Vieillot) 

 Gadow, Cat. Birds Brit. Mus., viii, 1883, 295, excl. syn. part. 



^Sylvia chivi Vieillot, Nouv. Diet. d'Hist. Nat., xi, 1817, 174 (Paraguay; based on 

 Coniramaestre Gaviero Azara, Apunt., ii, 34); Enc. M6th., 1823, 437. — Vireosylma chivi 

 Baird, Review Am. Birds, May, 1866, 337 (Vermejo R., Paraguay; s. e. Brazil; 

 Bahia?); Sclater and Salvin, Proc. Zool. Soc. Lond., 1869, 160 (Buenos Aires). — 

 Vlireosylvial olivacea var. chivi Baird, Brewer, and Ridgway, Hist. N. Am. Birds, i, 

 1874, 359.— Fireo chivi Gadow, Cat. Birds Brit. Mus., viii, 1883, 295, part (m 

 synonymy). — (?) Thamnophilus agilis {not Lanim agilis Lichtenst&ia?) Spix, Av. Bras., 

 ii, 1824, 25, pi. 34. 



Both this form and its northern representative, V. c. agilis, require careful study. 



