216 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



gg. Pale interspaces on rectrices not wholly rufous, but gray with 

 a rufous wash. 

 h. Abdomen barred with rufous. 

 I. Crown slightly grayer than the back; size larger, wings, 

 d^ over 220 mm. 9 over 230 mm. (eastern Honduras to 



Chiriquf) B. magnirostris argutus, ad. (p. 346) 



ii. Crown not grayer than the back; size smaller, wings, cf 

 not over 200 mm., 9 generally under 230 mm. (Guate- 

 mala; El Salvador). 



B. magnirostris direptor, ad. (p. 345) 

 hh. Abdomen streaked with rufous. 



i. Size larger, wings, cf over 220 mm., 9 over 230 mm. 

 (eastern Honduras to Chiriqui). 



B. magnirostris argutus, juv. (p. 346) 

 ii. Size smaller, wings, cf 220 mm. or less, 9 220-235 mm, 

 (Guatemala, El Salvador). 



B. magnirostris direptor, juv. (p. 345) 

 cc. Dorsal plumage blue-gray (adults) or brownish with pale markings (juv.). 



("subgenus Asturina"). 

 d. Underparts gray, barred with white; upperparts gray (adults). 

 e. Upperparts definitely, if not very strongly, barred with whitish. 

 /. The pale bars above distinctly obvious at first glance; white inter- 

 spaces below usually broader than dark bars (South America), 



B. nitidus nitidus, ad. (extralimital) " 

 ff. Pale bars above not distinctly obvious at first glance; less con- 

 trasting with darker ones; white interspaces on underparts 

 usually equal to or slightly narrower than dark bars (south- 

 western Costa Rica; Panama) B. nitidus blakei, ad. (p. 367) 



ee. Upperparts not definitely, if at all, barred. 



/. Tail with one complete white bar, second bar usually much 

 reduced to a series of small spots (British Honduras to north- 

 western Costa Rica) B. nitidus micrus, ad. (p. 364) 



ff. Tail with two more-or-less complete white bars, the first complete; 

 the second (more basal) often complete, but if not, always at 

 least a line of spots large enough to give the appearance of a 

 fairly definite bar. 

 g. Size larger, wings, cf over 250 mm., 9 over 270 mm. (south- 

 western United States, northwestern Mexico). 



B. nitidus maximus, ad. (p. 362) 



11 Falco nitidus Latham, Index Orn., i, 1790, 41 (Cayenne); Daudin, Trait6 

 d'Orn., ii, 1800, 122 (Cayenne); Vieillot, Nouv. Diet. Hist. Nat., xxiii, 1818,445; 

 Spix, Av. Bras., i, 1824, 19 (Marajo Island). — Astur nitidus Stephens, in Shaw's 

 Gen. Zool., xiii, pt. 2, 1826, 27 (Cayenne; Guiana). — Daedalion nitidus Lesson, 

 Traits d'Orn., 1831, 65. — Astiirina nitida Sclater and Salvin, Nona. Av. Neotr., 

 1873, 118, part; Sharpe, Cat. Birds Brit. Mus., i, 1874, 203; Hand-list, i, 1899, 257, 

 part; Brabourne and Chubb, Birds South Amer., i, 1912, 67. — Asturina nitida 

 nitida Swann, Synopt. List Accip., pt. 2, 1919, 55; Synop. Accip., ed. 2, 1922, 

 89; Monogr. Birds Prey, i, 1930, 432 (monogr.); Peters, Check List Birds of 

 World, i, 1931, 241. 



