1.32 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 flavoviridis.) 

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

 superciliary stripe more distinct and dusky lateral line of i^ileum 

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

 Vireosylva flavoviridis flavoviridis (p. 144) 

 tt. Larger (adult male averagini; wing 83, tail 5it.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. Superciliary stripe grayish white, distinct; pileum with a very 



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



Panama.) Vireosylva insulanus (p. 147) 



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

 tail-coverts paler sulphur yellow; a distinct dusky postocular 

 streak. [Vireoi^ijlrd chiri.) 

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

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

 13.3, tarsus 17); back, etc., nuich 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 cliivi 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 cliivi chivi (extralimital) ^ 



"'L{_anius'] agilis Lichtenstein, Verz. Doubl., 1823, no. 536 (Bahia, e. Brazil; coll. 

 Berlin Mua. ) .^Fliyllomanes agilix Burmeister, Syst. Ueb. Th. Bras., Aves, ii, 1856, 108 

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

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

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

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

 73. — V\_ireosylvla'] flavoviridis var. a^/7/.s Baird, Brewer, and Ridgway, Hist. N. Am. 

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

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

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

 (Bogota). — Vireo {Vireosylva) rirescens Baird, Rep. Pacific R. R. Surv., ix, 1858, p. 

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

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

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



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

 Contramaestre Gaviero Azara, Apunt., ii, 34); Enc. Meth., 1823, 437. — Vireosyhia 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). — 

 V[ireosylvia^ olivacea var. chivi Baird, Brewer, and Ridgway, Hist. N. Am. Birds, i, 

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

 synonymy). — (?) Thamnophilus agilis ( not Zrt«/».sor/(7/.s Lichtenstein?) Spix, Av. Bras., 

 ii, 1824, 25, pi. 34. 



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



