610 U. S. P. R. R. EXP. AND SURVEYS — ZOOLOGY— GENERAL REPORT. 
Family PENELOPIDAE. 
Ch.— Bill lengthened and rather slender; the end vaulted and hooked, covered by a horny plate, which extends backwards 
along the commissure ; the bill posteriorly, with a membrane, which covers the nasal fossae, the lores, and the orbital region, 
'eaving a broad, oval, free nasal aperture in the anterior portion of the nasal groove, without any peculiar scale above it. 
Plumage coarse. Wings much rounded, reaching to, or a littlo beyond, the base of the tail ; the outer four or five primaries 
much graduated, pointed, sometimes attenuated and emarginate ; secondaries lengthened. Tail of twelve feathers, lengthened, 
broad, even, or somewhat rounded. Legs moderately stout, the tarsus not very high, covered anteriorly by two rows of 
scutellae, behind by small oval scales in several series ; sometimes reticulated. Toes long and thin, the hinder one long, inserted 
low down on the heel, scarcely elevated above the plane of the others. The claws narrow, acute, and gently curved. 1 
The preceding characters, borrowed from Burmeister, refer to a family of hirds peculiar to 
Central and South America, many of them of very large size. They replace in these countries 
the Pliasianidae of the Old World, which are there entirely wanting, and, where abundant, 
furnish an important and excellent article of food. They are chiefly arboreal, living and 
nesting among, and in most cases on, the trees, usually moving about in large flocks. 
The family, as defined above, embraces three sub-families, the Cracinae, the Penelopinae, and 
the Oreophasinae, the first with the bill usually elevated, the culmen curved from the base. 
The sides of the head are generally well feathered, and the birds are of large size. The genera 
Crax and Pauxi, or Curassows and Hoccos, are known by the longitudinal open exposed 
nostrils, much anterior to the feathers, and rather low bill of the first, and the very much 
elevated bill, with the nostrils more vertical, basal, and concealed, of the other. 
The sub-family Penelopinae is the only one represented in our fauna, and by a single genus 
and species. In this the bill is weak, slender, longer than high, straight at the base above ; 
the portion covered with skin longer than the horny part, and the nostrils oval, elongated, and 
in the anterior portion of the groove, or extending to or beyond the middle of the bill. The 
sides of the head and the throat are more or less naked, with occasional feathers or hairs. The 
legs are as long as the middle toe without the claw. 
Of the sub-family Oreophasinae but a single species is known, the Oreophasis derbianus. In 
this the nasal groove is filled with feathers throughout, and there is an elevated truncated knob 
above the eyes. 
Of the Penelopinae, the typical genera, according to Gray, have the following characters : 
Ortalida. — Throat without wattles, but with two naked narrow streaks. Outer primaries 
broad to and at the ends. Hind toe two-thirds the lateral ones. 
Penelope. — Front of throat naked and wattled. Outer three primaries much attenuated and 
falcate, linear towards the end. Hind toe nearly equal to the lateral. 
Other genera are indicated by Reichenbach and Bonaparte, but these are sufficient to 
illustrate the characters of the single one belonging to the United States. 
ORTALIDA, M err em. 
Ortalida, Merrem, Av. rar. Icones et Desc. II, 178G, 40, (Gray.) Type Phasianus motmot, L. 
There is little to add in the way of characteristics to the diagnosis of this genus just given. 
But one species belongs to the United States, though several are found in Mexico and further 
eouth. 
1 Burmeister, Thiere Brasiliens, Vogel, II, 1856, 335. 
