| OCR Text |
Show 134 GEkus ONYCHOTES, KIDGWAY. Onycholes, RIDGWAY, Pr. Acad. Nat. Sci. Phi lad. Dec. 1^ 0,14* 2; type, O. ffruhen, nov. ap.- RIDGW. B. B. & R. Hist. N. Am. Birds, iii, ltf74, 252 ( outlines of generic characters). CHARACTERS.- General form and size most similar to that of species of Rupornis and Asturina. Bill very short, the tip unusually obtuse; cere very large and broad on top, its length almost equal to the chord of the culmen, and its greatest breadth equal to its length. Superior tomium slightly lobed; gonys slightly convex. Nostril nearly circular, or properly semi- circular or broadly ovate, its upper outline beiug less curved than the lower, more horizontal, its direction nearly parallel with the commissure of the bill; a cartilaginous tubercle is seen within the nostril in its upper portion. Outstretched feet reaching to or beyond end of the tail; tarsus long and slender, nearly twice the length of the middle toe; outer toe decidedly longer than the inner, which reaches the second phalangeal articulation of the middle toe; hind toe shorter than the inner. Scutellation of the tarsi and toes as in the typical Buteones, there being a continuous single series of transverse plates on the posterior face of the former; those on the auterior face Dumber 11- 12. Claws proportionally large, those of the first and second toes considerably exceeding their digits in length; they are much graduated in size to the outer, which is only half the length of the posterior one; their shape is normally buteonine. A well- developed web between outer and middle toes. Wing short and much rounded, reaching to about the middle of the tail, which is slightly rounded, and more than half as long as the wing. Remiges, 24; rectrices, 12. Third, fourth, and fifth quills longest, and nearly equal; first shortest; second about equal to sixth; outer five with inner webs emargiuated. Plumage generally dense and rather compact; tibial plumes short, reaching but little below the joint; upper third of the tarsus densely feathered in front and on sides. Lores quite densely covered with strong black bristles, these extending forward so as to cover the entire cere beneath the nostrils. Superciliary shield bare and prominent. This buteonine form has no very near relative among the American Fal conidce, nor, indeed, among those of the Old World; and the several striking peculiarities of detail in its external structure, besides the existing uncertainty regarding its precise habitat, and the unknown history of the ouly two specimens known to exist in collections, render this bird one of extreme interest. The general aspect of this peculiar hawk is that of the smaller short- winged Buteones of tropical America; it agreeing very nearly in size with " Buteola " minuta and B. brachyura. The fuligi nous plumage resembles also that of several species of the genus Buko< so much so, in fact, that the original specimen was labeled " Buteo fuliginosm Sclater "; while in the normal, or lighter phase, there is a somewhat close resemblance to the plumage of the latter of the two species above mentioned. There are very many strikiug peculiarities of external structure, however, which mark it as one of the most strongly characterized geuera in the group to which it belongs, notably the densely- bristled lores and lower jaw, the broad, high cere, short, obtuse bill, and very long claws. In the latter feature, there is a close approach to the genus Rostrkamus, in which, however, the feet are much weaker, and the tarsus conspicuously shorter, while otherwise the bird is extremely different |
