750 HULLKTIN 50, UNITED STATES NATIONAL MUSEUM. 



bands acrofss wirif^; an indistinct supra-aurioular streak of paler oliv^e; 

 chin whitish; throat, chest, and sides of breast pale brownish olive; 

 rest of under parts pale yellow (between sulphur and straw yellow), 

 the sides and flanks tintred with olive. 



Adult nude.— Ijaugih (skins), 112-133 (121.2); wing, 54-60 (56.5); 

 tail, 53-57 (54.7); exposed culmen, 9.5-11 (10.1); tarsus, 20-21.5(20.9).' 



Adult female.— lJG\^g{\\ (skins), 111-133 (111>.7); wing, 53-.58.5 (55.1); 

 tail, 52-55. 5 (53. 5); exposed cuhnen, 10-11(10.4); tarsus, 20-21.5 (20.9).- 



Nicaragua and Costa Rica (San Jose; Cartago; San Juan; Guaitil; 

 Grecia; Alajuela, etc.) 



Basileideru)f delaUrii Bonaparte, Compt. Rend., xxxviii, 1854, 383 (Nicaragua). — 

 Cabanis, Journ. fiir Orn., 1860, 325 (Costa Rica). — Cherrie, Proc. U. S. 

 Nat. MuH., xiv, 1891, 340 (crit.; Co^^ta Rica), 527 (San Jose, Costa Rica; 

 descr. young) ; Auk, ix, 1892, 22 (San Jose, Costa Rica; descr. nest and eggs) ; 

 Ex])l. Zool. Costa Rica, i, Aves, 1893, 14 (Boruca and Buenos Aires, s. w. 

 Costa Rica). 



BasUeuterus ddatlrei Lantz, Trans. Kansas Ac. Sci. for 1896-97 (1899), 223 

 (Grenada, Nicaragua). 



B\^aslle.uteTU8] delatrii Ridoway, Man. N. Am. Birds, 1887, 532, part. 



BasUeuterus nicsochrysus (not of Sclater, 1860) Baird, Review Am. Birds, 1865, 

 250, part (San Jose, Costa Rica). — iiAWKENCE, Ann. Lye. N. Y., ix, 1868, 95 

 (San Jose, Guaitil, and Grecia, Costa Rica). — Frantzius, Journ. fiir Orn., 

 1869, 294 (San Jose, Costa Rica).— Boucard, Proc. Zool. Soc. Lond., 1878, 

 52 (San Jose and Cartago, Costa Rica). — Salvin and Godman, Biol. Centr.- 

 Am.", Aves, i, 1881, 176, part (San Jose, Guaitil, Grecia, and Irazu, Costa 

 Rica). — Nutting, Proc. U. S. Nat. Mus., v, 1883, 499 (San Jose). — Zeledon, 

 Anal. Mus. Nac. Costa Rica, i, 1887, 107 (San Jose, Alajuela, Naranjo de 

 Cartago, Grecia, and Monte Redondo, Costa Rica). — Underwood, Il)is, 1896, 

 434 (Volcan de Miravalles, Costa Rica). 



[Basileuterus'\ mesochrysus Sclater and Salvin, Nom. Av. Neotr., 1873, 10, part 

 (Costa Rica). 



[^Badlenteriis delatfrli.] Subsp. a. Basileulcrus iiicsochriisiis Sharpe, Cat. Birds 

 Brit. Mus., X, 1885, 396, part (Grecia and Irazu, Costa Rica). 



BASILEUTERUS RUFIFRONS MESOCHRYSUS (Sclater). 

 SCLATER'S WARBLER. 



Similar to B. /-. delattrii, Init ])ack. etc., lighter and clearer (more 

 yellowish) olive-green, gray of hindneck lighter and clearer and more 

 strongly contrasted with olive-green of the back, and yellow of under 

 parts averaging brighter, with sides and Hanks more faintly tinged 

 with olive; tail relatively shorter. 



Adult v>^«Z.^— Length' (skins), 108-116 (110.7); wing, 55-59 (56.5); 

 tail, 48-53 (50.1); exposed cidmen, 10-11 (10.2); tarsus, 20-21 (20. 2). ^ 



Adult feiii(de.—ljQW)yi\\ (skins), 102-118 (109); Aving, 53-56(54.7); 

 tail, 47.5-54 (50.2); exposed culmen, 10-10.5 (10.3); tarsus, 20.5-21 

 (20.7).^ 



' Four si)ecimens. ^ Six specimens. ^ Three specimens. 



