POLYBOBUS. 125 



the arboreal habits, distinguish Ibycter ; and the linear nostril and the form of the 

 cere, which is described as "vertical in outline and nearly straight," are said to separate 

 Polyhorus from Milvago. 



Two well-defined species of Polyhorus are known, viz. : P. tharus (Molina), which 

 inhabits the greater part of South America, and is replaced in the northern portions 

 of the latter Continent, and throughout Central America even to the Southern United 

 States, by P. chermay (Jacq.) ; two closely allied forms of the latter have been treated 

 as distinct — P. lutosus, Ridgw., of the island of Guadalupe, off Lower California, and 

 P. pallidus. Nelson, of the Tres Marias Islands. 



The Polyhori are all terrestrial in their habits, usually frequenting open plains, and 

 feeding largely on carrion, like the Turkey Vultures, with which they often associate. 

 They are generally known by the name of " Caracara," but in Central America the 

 natives call them " Quebra'-hueso " * (bone-breaker). 



1. Polyborus cheriway. 



Falco cheriway, Jacq. Beitr. p. 17, t. 4 ^. 



Polyborus cheriway, Cab. in Schomb. Reis. Guiana, iii. p. 741 ^ ; Sharpe, Cat. Birds Brit. Mus. i. 

 p. 33 ' J Ridgw. Bull. U. S. Geol. & Geogr. Surv. i. p. 457 * ; Sumichrast, La Nat. v. 

 p. 235'; Salv. Cat. Strickl. Cat. p. 509°; Boucaid, P.Z.S. 1883, p. 457"; Belding, Pr. 

 U. S. Nat. Mus. vi. p. 344'; Nutting, Pr. U. S. Nat. Mus. vi. pp. 377 ", 389"; Ferrari- 

 Perez, Pr. U. S. Nat. Mus. ix. p. 168 " ; Zeledon, An. Mus. Nac. Costa Rica, 1887, p. 125"; 

 Herrera, La Nat. (2) i. pp. 177, 320"; Bendire, Life Hist. N. Amer. Birds, i. p. 315 "; 

 Fisher, Bull. U, S. Dep. Agric. no. 3, p. 128" ; Cherrie, Auk, 1892, p. 328 '=; Jouy, Pr. 

 U. S. Nat. Mus. xvi. p. 788 " ; Chapman, Bull. Amer. Mus. Nat. Hist. x. p. 35 ". 

 Polyborus brasiliensis, Sw. Phil. Mag. new ser. i. p. 366 (nee Gm.) ". 

 Falco plancus, Wagl. Isis, 1831, p. 516 (nee Gm.) ". 

 Polyborus tharus, Scl. P.Z.S. 1857, p. 211 (nee Molina)"; 1859, p. 368"; Scl. & Salv. Ibis, 



1859, p. 214 =^ P.Z. S. 1870, p. 838=*; Owen, Ibis, 1861, p. 67". 

 Polyborus audubonii, Cassin, Pr. Ac. Phil. 1865, p. 2 " ; Lawr. Ann. Lye. N. Y. ix. pp. 132 ", 

 207 "^ ; V. Frantz. J. f . Orn. 1869, p. 367 =" ; Grayson, Pr. Bost. Soc. N. H. xiv. p. 268 

 (pt.)-. 

 Polyborus tharus, var. audubonii, Lawr. Mem. Bost. Soe. N. H. n. p. 303 (pt.) " ; Bull. U. S. Nat. 



Mus. no. 4, p. 43 ". 

 Polyborus vulgaris, Dugfes, La Nat. i. p. 138" (nee Spix). 



Nigricans ; pilei plumis cristatis lanceolatis ; interscapulii plumis extus albido regulariter fasciatis ; torque 

 cervicali lactescenti-albo, maculis vel fasciis parvis nigris notato ; supracaudalibus medianis uropygio 

 concoloribus, lateralibus autem albis, vix nigro fasciatis ; rectricibus albidis, brunneo vel nigro trans- 

 fasciatis, et apicem versus nigricantibus, fasciam latam terminalem formantibus ; extemis vero nigricantibus, 

 vel albo late indentatis ; remigibus nigricantibus, primariis longioribus in medio grisescenl ibus, irregulariter 

 brunneo marmoratis vel fasciatim notatis : subtus nigricans, facie laterali et gutture toto cum colli 

 lateribus lactescenti-albis ; praepectore et pectore summo ochrascentibus, nigro cordatim fasciatis ; 

 abdomine imo, crisso et subcaudalibus ochrascenti-albis ; subalaribus ot axillaribus nigricantibus : rostro 

 flavicante, mandibula plumbescente, cera et regione orbitali Isete aurantiacis ; pedibus ttavis ; iride flava. 



* " Quebrantahuesos,'"' according to Sumichrast. 



