470 



tubercle not conspicuously exposed. Tarsus scarcely longer than mid- 

 dle toe; outer toe very much longer than the inner; posterior toe about 

 three-fourths as long as the iuner. Web well developed. Scutellte of 

 the tarsus small, irregularly hexagonal, scarcely larger in front; top of 

 toes with a continuous series of transverse scutellce. Claws normal, 

 long, and sharp. 



Pterylosis. — Remiges, 22, unusually developed, but the primaries much 

 larger than the secoiuiaries; fourth or fifth quill longest; first inter- 

 mediate between eighth and tenth ; outer five with inner webs very 

 hallowly sinuated.* Tail long and broad, much rounded. Plumage 

 generally compact and lustrous, but, soft and downy on the posterior 

 lower parts. Loral, orbital, and gular regions naked, the skin brightly 

 colored (deep red in life) ; crop naked, though the space is concealed 

 by the overlying feathers.! 



This genus is the most aberrant one of the group, and differs from 

 ail its associates in its very aerial and arboreal habits, its very short 

 tarsi, long toes, especially the outer and posterior ones, and in the 

 shallow sinuation of the inner webs of the primaries. Indeed, it resem- 

 bles so closely, in uiost of these points, the genus i2o6fr/i,awms, that without 

 an examination of its skeleton one would hardl}^ hesitate to i)Iace it next 

 that genus 4 The examination of its cranium and the coracoid appa- 

 ratus, however, shows plainly that it has no real affinity to that genus; 

 but that,- on the contrary, it is strictly polyborine. 



The two subgenera of Ihycter are not very strongly marked, and may 

 be barely defined by the following diagnosis: 



a. Size large. Bill slender, the tip much produced ; gouys barely 

 convex, nearly horizontal. Bare superciliary region very narrow. 



Ihycter. 



/S. Size small. Bill thick, the tip only slightly produced; gonys 

 strongly convex, decidedly ascending terminall3\ Bare supercil- 

 iary region very wide Daptrius. 



IBYCTER AMERICANUS. 



RED-THROATED IBYCTER. 



Falco americanus Bodd. Tabl. PL Eiil. 1783, 25. 



Ihycter americanus Gray, Gen.App. 1849, 1; List B. B. M. 1848, 28; Gen, and 

 Siibs^eii. 1855, 2; Hand List, i, 1869, 5.— Strickl. Orn. Syn. i, 1855, 22.— ScL. 

 P. Z. fc. 1857, 15 ; 1858, 449.— Schl. Mus. P.- B. Poly'bori, 1862, 9.— Pelz. 

 Verb. z.-b. Ges. Wien, 1862, 134 ; Orn. Bras. 1871, 2, 392.— Scl. &, Salv. P. Z. 

 S. 1864, 358 (Panama); ib. 1870, 838 (coast of Honcinras).— Gurney, Cat. Eapt. 

 Norw. Mus. 1864, 29.— Lawr. Ann. N. Y. Lye. ix, 1868, 132 (Costa Eica).— 

 Salv. P. Z. S. 1870, 214 (Veragua).— Ridgw. Cat. Falc. Mus. Bost. Soc. May, 



1873, 11.— Scl. & Salv. Nom. Neotr. 1873, 122.— Sharpe, Cat. Ace. B. M. 



1874, 35. 



Falco aqnilinus Gm. S. N. i, 1788, 280.— Temm. Tab. M^tla. 1836, 2. 

 Circaetus aquiUnus Cuv. Reg. An. i, 1817, 317. 



Ihycter aquilimts ViG. Zool. Jonni. i, 1824.— Steph. Zool. siii, 1826, pt. 2, 10. — 

 Gray, Gen. B. 2 ; ed. 2, 2 ; fol. i, 1844, 9, sp. 1.— Kaup, Mus. Senck. 1845, 262.— 

 Cabaj!^. Schomb. Eeis. Guian. iii, 1848, 742.— Bonap. Consp. i, 1850, 12.— 

 Cassin, p. a. N. S. Pbilad. 1860 (Turbo and Truando, N. G. ; notes on habits 

 and voice). 



* Very much as in the buteonine genera Cymindis and Bostrliamus. 



t According to Nitzsch, the pterylosis of 7. (Daptrius) ater is very similar to that of 

 the Buteones ; biit all the tracts are narrow, the outer branch of the inferior tract 

 broader and quite free, Avith a strong hook at the end, the dorsal portion of the spinal 

 tract short, the anterior half sparsely feathered, posteriorly densely feathered. The 

 remiges are 22 in number. 



X Schlegel (Mus. P.-B. Polybori, 1862, p. — ) places the species of Bostrliamus in Ihycter t 



