596 BULLETIN 5 0, UNITED STATES NATIONAL MUSEUM 



Caracara Cuvier, R6gne Anim., i, Dec. 1816, 316, in text (in vernacular only!). — 

 Merrem, in Ersch and Gruber's Encycl., sect. 1, xv, 1826, 159. — Lesson, 

 Man. d'Orn., i, 1828, 87. 



Polyborinae with relatively long neck and legs, ambulatory (gra- 

 dient) progression, with the bill deep and much compressed and with 

 narrow (linear) oblique nostrils in upper anterior portion of cere. 



Bill deep (vertically) and compressed, the depth of maxilla at 

 anterior edge of cere equal to about half the chord of culmen, its 

 width at same point equal to about two-thirds its depth; culmen 

 strongly convex, the tip of maxilla strongly, but not acutely uncinate; 

 maxillary tomium nearly straight to faintly concave, but with more 

 or less distinct slight sinuosities, especially near base of unguis, where 

 the falconine "tooth" is indicated by a faint concavity; mandibular 

 tomium nearly straight for greater part, but distinctly though slightly 

 convex distally, the sub terminal portion, like that of the maxillary 

 tomium, more or less irregular or "wavy," anterior outline of cere 

 vertical, nearly straight; nostril small, linear-oblong, obliquely vertical 

 (its upper end the posterior one), situated in upper anterior portion 

 of cere. Wing long and pointed, primaries nearly twice as long as 

 secondaries, rigid, the third to fourth (from outside) longest, the first 

 (outermost) shorter than sixth (sometimes shorter than seventh) ; the 

 inner webs of the outer four distinctly and of the fifth indistinctly 

 sinuated; remiges twenty-four. Tail about two-thirds as long as 

 wing, slightly rounded or nearly truncate, the rectrices (12) rather 

 rigid, with firm webs and strong shafts, their tips broadly rounded. 

 Tarsus much longer than middle toe without claw, the acrotarsium 

 with 4 to 6 large transverse scutella on lower portion (continuous 

 with those on upper side of toes), the remaining portion with two 

 parallel series of alternating hexagonal, more or less longitudinal 

 scales, the planta tarsi with smaller, more quadrate, scales, for the 

 most part arranged in two parallel series; outer toe longer than inner 

 toe, the latter longer than hallux; claws normal, but rather long and 

 not strongly curved. 



Skull most like that of Phalcoboenas, but premaxillaries more com- 

 pressed, dome of cranium more depressed with upper outline more 

 horizontal, and the nasal bones and palatines of different form. 

 Nostrils closely approximated in upper edge of the nasals, oblong and 

 oblique, their upper end the posterior one. Posterior outline of pal- 

 atines nearly truncate with posterolateral outline forming an abrupt 

 angle. Mandible with an acute-oblong vacuity posterior to the mid- 

 dle portion. Posterior margin of sternum with a pair of widely 

 separated, ver}'^ deep, rounded indentations. Tarsus much longer 

 than femur, in proportion to tibia= 3.50:4.50. First and second 

 bronchial semirings very prominent and wide apart, thus leaving a 



