36 FALC0NID2E. 



Falco formosus, Lath. Ind. Orn. i. p. 38 ("1790). 



Falco nudicoUis, Daud. Traite, ii. p. 79 (1800). 



Circaetus aquilinus, Cuv. Rvrpie An. i. p. 317 (1817). 



Gymnops aquilinus, AS)j/.r, Av. Bras. i. p. 11 (1824). 



Ibycter aquilinus, Viq. Zool. Journ. i. p. 336 (1824); Gray, Gen. B. 



i. p. 9 (1844) ; Cab. in Schomb. Reis. Guian. iii. p. 742 (1848) ; 



Bp. Consp. i. p. 12 (1850). 

 Polyborus aquilinus, Less. Man. d'Orn. i. p. 88 (1828). 

 Ibvcter ameiicanus, Gray, Gen. B. App. p. 1 (1849) ; Strickl. Orti. 



'Syji. p. 22 (1855) ; Schl. Mvs. P.-B. Polvbori, p. 9 (1802) ; Pek. 

 Verh. z.-b. Wien, 1862, p. 134 ; id. Orn. Bras. pp. 2, 392 (1871) ; 



Gurney, Cat. liapt. B. Nuriv. Mus. p. 29 (1864) ; *S'e/. 8f Salv. 



Nomencl. Ai\ Ncotr. p. 122 (1873). 

 Milvago nudicollis, Burm. Th. Bras. ii. p. 37 (1856). 

 Ibycter formosus, I'elz. Verh. z.-b. Wien, 1862, p. 134 ; id. Orn. Bras. 



pp. 2, 392 (1871) ; Scl. ^- Salv. Nomencl. Av. Neotr. p. 122 (1873). 



Adult male. Black, with steel-green reflections and sometimes 

 slightly shaded with ashy grey ; ear-covorts decidedly shaded with 

 ashy grey ; entire abdomen, thighs, and under tail-coverts white ; 

 bare space before the eye and throat deep red; cere blue; man- 

 dibles yellow ; iris deep red. Total length 19-5 inches, culmen 1-6, 

 wing 13'6, tail 9-2, tarsus 2. 



Female. Similar to the male, but larger. Total length 24 inches, 

 wing 15-5, tarsus 2-3 *. 



Hah. The whole of Amazonia, Ecuador, and Columbia, reaching 

 to the southward along eastern Brazil as far south as the Tropic of 

 Ca])ricorn, and ranging along the western coast of Central America 

 to Guatemala and Honduras. 



3. Ibycter megalopterus. 



Aquila megaloptera, Meyen, Beitr. p. 64, pi. 7 (1834). 

 Phalcobjenus montanus, If Orb. Toy. Am. Merid. Ois. p. 51, pi. 2 



(1835). 

 Milvago montanus, Dartv. Voy. Beayle, Birds, p. 13 (1841) ; Pelz. 



Verh. z.-b. Wien, 1862, p. 135. 

 Milvago megalopterus, Banvin, Voy. Bear/Ie, Birds, p. 13 (1841); 



Gray, Cat. Accipitr. 1848, p. 30 ; Strickl. Orn. Syn. p. 21 (1855) ; 



Grat/, Hand-l. B. i. p. 6 (1869) : Scl. &■ Salv. Nomencl. Av. Neotr. 



p. 122 (1873). 

 Polvborus megalopterus. Cab. Sf Tschudi, Favn. Peruana, pp. 16, 78 



(1845) ; Schl. Mm. P.-B. Polybori, p. 4 (1872). 

 Phalcobffinus megalopterus, Bp. Consp. i. p. 13 (1850) ; Gurnet/, Cat. 



Rapt. B. Norw. Mus. p. 24 (1864). 



* Von Pelzeln's I. formosus (ex Lath.) is surely nothing but the female of J. 

 americanus, witness sexed specimens in the collection of Messrs. Salvin and 

 Godman. 



I 



