182 
Total length, 8 inches; bill, ;; wing, 44; tail, 24; tarsi, li. 
Hab. Mexico ; locality unknown. In the collection of the Earl of 
Derby. 
Remark.—This species is of the same form and nearly of the same 
size as O. Virginiana. 
Orryx PEecroratis. Ort. vertice et nuchd nigrescenti-fuscis ; lined 
angustd albd frontali super oculos et per nucham ductd ; plumis 
auricularibus, colli lateribus, et pectore nigris ; guld albd; abdo- 
mine, lateribus et crisso, cervinis ; plumis lateralibus inferioribus, 
ad apices nigro alboque guttatis dorso superiore, humeris scapulis- 
que castaneis, tectricibus alarum, et caude, tertiariis, et dorso imo, 
cinereo-fuscis ; plumis omnibus corporis superioris cervino pallideé 
marginatis, et punctatis. 
Crown of the head and back of the neck blackish brown; a narrow 
stripe of white crosses the forehead, passes over the eye, and extends 
down the back of the neck below the occiput; ear-coverts, sides of 
the neck and chest, black ; throat white ; abdomen, flanks and under 
tail-coverts fawn-colour; the tips of the feathers on the lower part 
of the flanks spotted with black and white; the upper part of the 
back, scapularies and shoulders, chestnut brown; wing-coverts, ter- 
tiaries, back and upper tail-coverts greyish-brown; all the feathers 
of the upper surface margined and speckled with very light fawn- 
colour, which on the secondaries assumes the form of distinct bars ; in 
addition to these marks the scapularies, secondaries, back and rump, 
are minutely freckled with brown; the strongly contrasted markings 
giving all the upper surface a bespangled appearance; primaries 
brownish-grey ; tail-feathers bluish-grey ; some of them freckled on 
the margin with buff ; bill black; feet flesh-white. 
Total length, 7 inches; bill, $; wing, 4; tail, 23; tarsi, 12. 
Hab. Mexico; locality unknown. In the collection of the Earl of 
Derby. 
Remark.—Of the same form, but smaller in size than O. Virginiana. 
Orryx castavgeA. Ort. fronte guldque nigris ; lined superciliart 
albd obsoletd usque ad occiput, et super hanc lined nigrd vertice, 
nuchd, dorso superiore, humeris, pectore, et lateribus saturate cas- 
taneis ; uropygio, tectricibusque caude@ castaneis nigro irroratis, 
fasciatis, et punctatis ; plumis abdominalibus albis, nigro undatim 
fasciatis lateralibus, guttis albis supra nigro cinctis, ornatis ; his 
notis omnibus lucidis. 
Forehead and throat black; an indistinct line of white runs 
over the eye to the occiput, above this another indistinct line of 
black ; crown of the head, back of the neck, upper part of the back, 
shoulders, chest and flanks, deep rich chestnut; the feathers on the 
sides of the neck with a black stripe down the centre and an oblong 
patch of white down the outer web; the tertiaries and some of the 
scapularies margined with deep fawn-colour, bounded within by an 
indistinct line of black ; these feathers are also crossed with indistinct 
bars and freckles of black ; ramp and upper tail-coverts rich chestnut, 
minutely freckled, barred and dotted with black; feathers on the 
