60 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Adult female. — Pileum pale cinnamon to russet, more or less dis- 

 tinctly streaked with dusky; back, scapulars, rump, and upper tail 

 coverts plain olive; tail brownish olive or olive-brown; general color 

 of wings olive (paler on edges of primaries), the lesser and middle 

 wing-coverts darker (sometimes blackish), each with a terminal spot 

 of buff, the greater coverts with a buffy spot on tip of outer web; 

 auricular region olive or buffy grayish, very narrowly streaked with 

 whitish or buffy; suborbital and malar regions pale bufty, barred or 

 flecked with dusky; chin and throat dull buffy whitish, usually with 

 more or less distinct narrow streaks of dusky; rest of under parts 

 buff (more or less deep) medially, this passing into olive on sides and 

 flanks, the chest sometimes streaked with dusky; under wing-coverts 

 mostly pale buff or dull buffy whitish, the inner webs of remiges 

 broadly edged with the same; maxilla dusky brown, mandible dull 

 whitish (in dried skins); legs and feet horn color (in dried skins); 

 length (skins), 97-112 (103); wing, 56-60.5 (58.2); tail, 29-35.5 

 (32.2); culmen, 14.5-16.5 (15.4); tarsus, 18-21 (19.6); middle toe, 

 11-12.5 (11.9).« 



ImTYiature male. — Similar to the adult female but grayer above and 

 more whitish beneath. 



Costa Rica (Angostura; Talamanca; San Carlos; La Balsa; Dos 

 Novillos; Siquirres; Guacimo; Guapiles; El Hogar; Carillo; La Chris- 

 tina; Rio Reventazon; Rio Sicsola; Miravalles; La Vijagua). 



Dysithamnus striaticeps Lawrence, Ann. Lye. Nat. Hist. N. Y., viii, May, 1867, 

 130 (Angostura, Costa Rica; coll. U. S. Nat. Mus.); ix, 1868, 107 (do.).— 

 Frantzius, Journ. fiir Orn., 1869, 305 (Costa Rica). — Boucard, Proc. Zool. 

 Sec. Lond., 1878, 60 (San Carlos, Costa Rica). — Zeledon, Anal. Mus. Nac. 

 Costa Rica, 1887, 115 (Angostura, Costa Rica). — Sclater, Cat. Birds Brit. Mus., 

 XV, 1890, 223 ("Valza," i. e.. La Balsa, Costa Rica). — Salvin and Godman, 

 Biol. Centr.-Am., ii, 1892, 208.— Underwood, Ibis, 1896, 440 (Volcan de 

 Miravalles, Costa Rica). — Carriker, Ann. Carnegie Mus., vi, 1910, 606 

 (Caribbean foothills, 800-1,500 ft., Costa Rica; habits; descr. nest and eggs). 



[Dysithamnus] striaticeps Sclater and Salvin, Nom. Av. Neotr., 1873, 70. — 

 Sharpe, Hand-list, iii, 1901, 19. 



Genus MYRMOTHERULA Sclater. 



Myrmotherula Sclater, Proc. Zool. Soc. Lond., 1858, 234. (Type, Musdcapa 



pygmsea Gmeliu.) 

 Myrmotherium (emendation) Cabanis and Heine, Mus. Hein., ii, July, 1859, 



12, footnote. 



Very small Formicariidse (length less than 100 mm.) with bill 

 slender, nearly as long as head, tail less than two-thirds (sometimes 

 less than half) as long as wing, and plumage either conspicuously 

 streaked or else mostly uniform gray or slate color. 



Bill slender, depressed, nearly as long as head, its width at frontal 

 antiae very much greater than its depth at same point, and equal to 

 about half the distance from nostril to tip of maxilla or less; culmen 



oTen specimens. 



