BIEDS OF NORTH AND MIDDLE AMERICA. 279 



KEY TO THE SPECIES AND SUBSPECIES OF SITTASOMUS. 



a. Pale band arroaa inner web of remigea very sharply defined, very distinrt on 

 serondariea as well as on primaries, and in color distinctly yellowish. 

 h. Tail and secondaries rufous-chestnnt or deep cinnamon-rufous. 

 c. Under parts olive-yellowish. (Southeastern Brazil, etc.) 



Sittasomus erithacus (extralimital)." 

 cc. Under parts grayish olive or olive-grayish. 

 d. Back mixed rusty and olive. 

 e. More olivaceous, with much smaller bill; under wing-coverte and band 

 across inner web of remiges deeper yell(nvish. (Southwestern Brazil, 



etc.) Sittasomus chapadensis (extralimital).'' 



cc. More grayish, with much larger bill; under wing-coverts and band across 

 inner webs of remiges paler yellowish. (Upper Amazon Valley.) 



Sittasomus amazonus (extralimital). c 

 dd. Back uniform russet brown. {Sittasomus sylvioides .) 



c. Smaller (male averaging, wing, 77.1; tail, 73.5; exposed <'ulmen, 14 mm.). 

 (Southeastern Mexico to Costa Rica.) 



Sittasomus sylvioides sylvioides (p. 280). 

 ee. Larger (male averaging, wing, 84; tail, 77.5 or more; ex})osed culmen, 

 15.4 or more). 

 /. Tail and bill shorter (tail averaging 77.5, exposed culmen 15.4). (Pan- 

 ama.) Sittasomus sylvioides levis (p. 282). 



jf. Tail and bill longer (tail averaging 81, exposed culmen 1G.5). (Western 



Mexico.) Sittasomus sylvioides jaliscensis (p. 283). 



hh. Tail and secondaries clear tawny. (Western Ecuador.) 



Sittasomus sequatorialis (extralimital). d 

 an. Pale band across inner web of remiges not sharply defined, very indistinct on 

 secondaries, in color white or yellowish white. (Tobago.) 



Sittasomus griseus (extralimital)." 



« D[endrocolaptes] erithacus Lichtenstein, Abh. Konigl. Akad. Wissensch. Berlin, 

 for 1820-21 (1822), 259, 26G, pi. 1, fig. 2 (Province of Sao Paulo, s. Brazil; coll. Berlin 

 Mu3.). — [Sittasomus] erythacus Bonaparte, Consp. Av., i, 1850, 209. — Sittasomus eri- 

 thacus Lafresnaye, Rev. Zool., 1850, 589; Sclater, Cat. Birds Brit. Mua., xv, 1890, 

 119; Ridgway, Proc. U. S. Nat. Mus., xiv, 1891, 508 (monogr.). — Sittasomus sylvicllus 

 Temminck, PI. Col., livi-. 12, Sept. 27, 1823, text to pi. 72, fig. 1; Menegaux and 

 Hellmayr, Mem. Soc. Hist. Nat. d'Autun, xix, 190G, 95 (Goyaz, Brazil; crit.).^ — Sit- 

 tasomus sylvicllus sylvicllus Hellmayr, Novit. Zool., xv, 1908, 63 (Gt)yaz and Faz. 

 Esperan^a, Brazil). — Acanthurus microrhynchus Bertoni, Aves Nueves del Paraguay, 

 1901, 72. — S{ittasomus\ olivaccus Maximilian, Beitr. Naturg. Bras., iii, 1831, 1146. 



b Sittasomus chapadensis Ridgway, Proc. U. S. Nat. Mus., xiv, no. 877, Oct. 31, 

 1891, 509 (Chapada, Matto Groeao, s. w. Brazil; coll. Am. Mus. Nat. Hist.); Mene- 

 gaux and Hellmayr, M6m. Soc. Hist. Nat. d'Autun, xix, 1906, 95 (Chiquitoa, Bolivia; 

 crit.). — Sittasomus sylvicllus chapadensis Hellmayr, Novit. Zool., xv, 1908, 63 (Rio 

 Thesouraa, Brazil; crit.). 



c Sittasomus amazonus Lafresnaye, Rev. et Mag. do Zool., 1850, 509; Ridgway, 

 Proc. U. S. Nat. Mus., xiv, 1891, 509 (monogr.); Menegaux and Hellmayr, M^m. 

 Soc. Hist. Nat. d'Autun, xix, 1906, 96 (Yungas, Bolivia; up. Amazon). — Sittasomus 

 olivaccus amazonus Hartert, Kat. Vogelsamml. Senckenb., 1891, 110 (Bolivia). 



d Sittasomus sequatorialis Ridgway, Proc. U. S. Nat. Mus., xiv, no. 877, Oct. 31, 

 1891, 509 (Guayaquil, w. Ecuaddr; coll. U. S. Nat. Mus.). 



« Sittasomus griseus Jardine, Ann. and Mag. N. H., xix, 1847, 82 (Tobago); Ridg- 

 way, Proc. U. S. Nat. Mus., xiv, 1891, 510 (monogr.). 



