FALCONID^ — POLYBOBIN^: CABACARAS. 
539 
the above species in dark rufous lower parts, and dusky, mottled inner webs of primaries." 
(Kidgway.) Cuba; Florida. 
511. F. fuscicoerules'ceiis. (Lat. fiiscus, dark; ccerulescens, bluish.) Femoral Falcon. 
Aplomado Falcon. Quite diflferent from any of the foregoing species, though belonging to 
the sparrow hawk group (Tmnuneulus) ; it has been made a separate subgenus [Bhyncho- 
falco). Bill robust, with large cere; irregular scutellation of tarsus continuous on the toes; 
tarsus a little longer than middle toe without claw ; 2d and 3d quills longest ; 1st about equal 
to 4th ; 1st and 2d emarginate on inner webs ; 2d and 3d sinuate on outer webs. Size 
medium (among the smaller falcons) ; form slender; sexes alike. Adult 9 • Above, uniform 
plumbeous ; tail with about 8 narrow white bars, and tipped with white, as are the secondaries ; 
primaries with numerous narrow white bars on inner webs, mostly being isolated transverse 
spots, reaching neither shaft nor inner edge of the feathers ; the same pattern less definitely 
continued on to the secondaries. Side of head with a broad white or tawny postocular stripe, 
continuous with the narrowly white forehead, shading into orange-brown on the nape, where 
confluent with its fellow ; auriculars mostly white, set in the black of the side of the head, but 
continuous with the white of the throat, so that a black supra-auricular stripe meets a black 
mystacial stripe under the eye. Sides of body and a broad belly-band black, with or without 
numerous narrow white bars ; the extent of this black very variable ; it usually leaves the 
breast white or tawny, but in younger specimens the whole breast is streaked with black on a 
tawny ground. Throat usually white. Lining of wings blackish, spotted with white, the 
border mostly white or tawny. Flanks, flags, and crissum uniform tawny or orange-brown. 
Young sufficiently similar, but upper parts rather dark brown than plumbeous. Length 15.00 
or more ; wing 10.00-11.00 ; tail 7.00-8.00 ; tarsus 1.75 ; middle toe without claw 1.50. A 
handsome hawk, well-known and wide-ranging in S. and C. Am., reaching just over our Mex- 
ican border. Nest in trees or bushes; eggs 1.80 X 1-65, white, finely dotted with light brown, 
overlaid with blotches of dark brown. 
46. Subfamily POLYBORIN/E: Caracaras. 
Anatomical characters of Falconince proper, in the scapular arrangement by which a pro- 
cess of the coracoid reaches the clavicle, the central tubercle of the extensively ossified nasal 
bones, the anterior keel of the palate, and the superorbital shield in a single piece ; external 
characters very unlike those of FalconincE, and general aspect vulturine. Bill toothless. 
Sternum single-notched on each side behind. Three or more primaries sinuate-emarginate on 
inner webs ; 3d or 4th longest ; 1st shorter than 5th. A small but remarkable group, com- 
bining some of the essential characters of falcons with others more vulture-like ; the species are 
chiefly terrestrial, rather sluggish, and feed much on carrion. The genera are Polyhorus, 
Phdlcohcenus, Senex, Milvago, Ibycter, and Daptrius, all confined to America. 
179. POLY'BORUS. (Gr. noXv^opos, pohjhoros^ very voracious. Fig. 379.) CaracarasI Bill 
long, high, much compressed, little hooked, the commissure nearly straight to the deflected 
end ; cere ending anteriorly in a nearly straight vertical line ; nostril high in the front upper 
corner of the cere, linear, oblique, its posterior end uppermost, its tubercle concealed. Chin 
and sides of head bristly, extensively denuded; a naked pectoral area; an occipital crest. 
Tibiae shortly flagged. Tarsus nearly twice as long as middle toe without claw, almost 
entirely naked, chiefly reticulate, but in front broadly scutellate in single or double row; 
lateral toes of about equal lengths ; hind toe much the shortest ; claws long and little curved. 
Wings very long, with 3d and 4th quiUs longest, 2d and 5th next, 1st shorter than 6th or 7th ; 
outer 4 or 5 emarginate. Tail rounded, about f as long as wing. Comprising two or three 
species of large vulture-like carrion hawks, of terrestrial habits, and ambulatorial, not salta- 
torial, gait, P. cherivcuj, P. auchthoni, and P. lutosus, of the warmer parts of America. 
• P. au'duboni. (To J. J. Audubon.) Common Caracara. Ad. <^ 9 : General color blackish. 
