128 FALCOXID^. 



Milvago chimachima, Salv. P. Z. S. 1870, p. 214'; Ridgw. Bull, U. S. Geol. & Geogr. Surv. i. 



p. 468\ 

 Ibyder chimachima, Sharpe, Cat. Birds Brit. Mus. i. p. 39 ". 



Supra saturate brunneus, notaei plumis vix griseo vel grisescenti-albo marginatis ; supracaudalibns medianis 

 brunneo et ochraceo late regfulariter transfasciatis, lateralibus ochraceis, baud faseiatis ; rectricibns ochraceis, 

 bmnneo 7-transfasciatis et fascia lata brunnea subterminali omatis; remigibus brunneis, tectricibus 

 primarionim grisescenti-albo terminatis ; primariis extns versus basin grisescentibus, brunneo marmoratis, 

 intus ochraceo indentatis ; pUeo cristato et cervice toto ochraceis, fascia angusta supra-auriculari nigra ; 

 facie laterali et corpore subtns toto cum subalaribus et axUlaribus ochraceis ; tectricibus primariorum 

 inferioribus brunneis vel brunneo faseiatis : rost.ro cyauescenti-albo, ad apioem albo : cera, loris et 

 palpebris aurantiaco-flavis ; pedibus plumbeis ; iride griseo-brunnea. Long, tota circa 15"5, alae ll'O, 

 cauds 7*6, culm. 1-05, tarsi 1"95. (Descr. exempl. ex Calobre. Mus. nostr.) 



Juv. Brunneus, pileo et cervice dorso concoloribus et minute ochraceo striolatis ; facie laterali brunnea : 

 subtus brunneus, plumis omnibus triangulariter ochraceo vel ocbrascenti-albo notatis ; pectore et hypo- 

 chondriis brunneo et ochraceo transfasciatis ; abdomine imo et subcaudalibus ochraceis concoloribus. 

 (Descr. exempl. juv. ex Matto Grosso. Mus. nostr.) 



Hob. Panama, Calobre, Chepo (E. Arce ^ *), Bay of Panama {Kellett & Wood ^). — South 

 Ameeica from Colombia to Paraguay ^ ^. 



This is a common South-American Hawk, and extends northward to Colombia and 

 thence to the Isthmus of Panama * ^. Kellett and Wood procured a specimen many 

 years ago in the Bay of Panama, and Arce sent us examples from Chepo and Calobre ^. 



Naturalists who have travelled in South America state that it has the same habits as 

 Polyhorus. 



IBYCTER. 



Ibyder, Vieillot, Anal. p. 22 (1816) ; Sharpe, Cat. Birds Brit. Mus. i. p. 34 (1874) ; Ridgw. Bull. 

 U. S. Geol. & Geogr. Surv. i. p. 469 (1876). 



Ibyder, as defined by Mr. Eidgway, differs from Polyhorus and Milvago in the 

 following characters : — " Tarsus scarcely longer than the middle toe ; outer toe very 

 much longer than the inner one, which is but little longer than the posterior toe ; 

 inner webs of primaries slightly sinuate ; nostril circular, situated near the middle of 

 the cere, its tubercle either concealed or exposed ; anterior outline of the cere doubly 

 curved ; tarsus without transverse scutellae either in front or behind. Habits strictly 

 arboreal." 



Two species are recognized : /. americanus, which inhabits the greater part of South 

 and Central America, and /. ater, which is confined entirely to the South-American 

 Continent. The latter is a small species, with a thicker and somewhat differently 

 shaped bill, and a more broadly defined bare eyebrow. 



Mr. Ridgway refers /. ater to a separate subgenus, Daptritts. 



1. Ibycter americanus. 



Aigle d'Amerique, Buff. PI. Enl. 417 '. 

 Red-throated Falcon, Lath. Gen. Syn. i. p. 97% 



