O R T 
female is of a dull green hue; the wings are 
dufky ; the tail is a dirty green ; and the tips of 
the exterior feathers are whitifh. 
Oriole, YelloW-Shouldered. This bird, 
which is a native of Holland, and feme other 
places on the continent, has a dufky bill ; the fea- 
thers of the back part of the head are turned up- 
wards, and curled; and the neck, back, bread:, and 
belly, are black. The firft row of coverts of the 
wings are of a bright yellow hue ; the reft, with 
the fcapulars and fecondaries, are black, edged 
with pale brown ; and the primaries are dufky. 
The tail is very long and black ; and the legs are 
dufky. 
ORNITHOLOGY. That particular branch 
of natural hiftory wliich teaches the knowledge of 
the natures, kinds, and forms, of birds; their ceco- 
nomy and ufes. 
LinnzEus, whofe fyftem has moft obtained, ar- 
ranges the whole clafs of birds under fix orders, 
according to the different figures of their beaks : 
namely, the accipitres, or birds with hooked 
beaks, comprehending four genera, and feventy- 
eight fpecies; the picae, or birds with convex and 
compreffed beaks, containing twenty-two genera, 
and two hundred and forty-three fpecies; the an- 
feres, comprehending fuch birds as have deprefled 
and dentated, or ferrated beaks, including twelve 
genera, and an hundred and fix fpecies ; the 
grallse, or thofe furniftied with fubcylindric and 
obtufe beaks, including eighteen genera, and an 
hundred and twenty-feven fpecies ; the gallins, 
or birds which have the beak of a convex form, 
but crooked, and the upper chap imbricated, 
comprehending feven genera, and thirty-nine fpe- 
cies; and the pafferes, or birds with conic and 
lharp-pointed beaks, including fifteen genera, 
and three hundred and thirty-feven fpecies. 
OROSPIZA. An appellation given by the 
ancient naturalifts to the brambling, or mountain- 
finch. 
ORPHEUS. A fiih caught in the Archipe- 
lago, of a broad and flat figure, and of a fine pur- 
ple colour. The eyes are large and prominent; 
and the teeth are ferrated. It has only one dorfal 
fin, the anterior rays of which are prickly, the 
others fotl; and the anus is extremely fmall. 
Under this defcription the Orpheus of the an- 
cient Greeks is intended ; but the moderns call a 
very different fifti by the fame name. This is a 
fpecies of the fparus, of a flat figure, but very 
thick, with a fmall mouth. The body is covered 
with minute rough fcales, which adhere very firmly 
to the flefli ; the tail is even ; the back and fides 
are black; the belly is white; the head is reddifh; 
and a large black fpot appears at the root of the 
tail. The fins are elegantly diverfified with va- 
rious colours; and the anterior rays of the dorfal 
fin are prickly, the others being fmooth. This 
filh fometimes weighs twenty pounds; and it's 
flefli is much admired. 
ORTHOCERATITES. An appellation given 
by fome naturalifts to a fpecies of fea-fliell, fre- 
quendy found foffile, but very feldom in a recent 
(late. It is called by others polythalamium, and 
tubulus marinus concameratus. It is ufually 
ftraight, but fometimes it's extremity is twifted 
like the cornu ammonis. 
ORTHRAGORISCUS. A name given by 
fome ichthyologifts to the fifli more commonly 
known by that of the moh; in Englilh, the fun- 
filh. 
OSP 
ORTOLAN. This bird, which the Venetians 
call tordino, is about the fize of the yellow-ham- 
mer, and very much refembles it. It's length, 
from the tip of the bill to the extremity of the 
tail, is feven inches; and the expanfion of the 
wings is ten inches and a half. The bill of the 
male is fliort and reddifli ; the throat and breaft 
are cinereous ; the lower parts of the body, as far 
as the tail, are reddifti ; and the rump is of a deep 
red colour. 
The Ortolan differs from the reed-fparrow in 
having different haunts, in being of a redder co- 
lour, and in wanting the ring about the neck; be- 
fides, there is a yellow fpot under the throat, 
which is not to be found in the reed-fparrow. The 
flefti is exceedingly rich and delicate; for which 
reafon it brings a high price in fome countries. 
Thefe birds are extremely numerous in Lan- 
guedoc and Provence, where they are ufually 
caught from the middle of April to the latter end 
of Auguft. They are alfo plentiful at Smyrna, 
and in feveral parts of Italy. 
Aldrovandus enumerates fix varieties of this 
kind; one of which has the extremities of the 
prime-feathers of the wings white; another entirely 
white; a third has a yellowifli afh-coloured head; 
a fourth a green neck, with a red bill j a fifth is of 
a pale colour over the whole body, except the 
breaft and the extremities of the wings, which 
are white j and a fixth variety refembles the white- 
throat. 
ORTYGOMETRIA. A name fometimes 
given to the daker-hen. See Daker-Hen. 
OS AUREUM. An appellation given to a 
fpecies of cochlese of the lunar kind ; or of that 
genus having a round mouth, which in the Os 
Aureum is of a fine yellow colour. 
OS ARGENTEUM. A fpecies of Ihell-fifh of 
the round-mouthed fnail, or lunaris cochlea-kind. 
The round aperture or mouth of this fhell is of a 
very elegant filver-colour. 
OSMERUS. A genus of fifli of the mala- 
coptcrygious, or foft- finned kind : the charafters of 
which are; that the branchioftege membrane con- 
tains feven or eight bones on each fide ; the back 
and belly fins are placed at the fame diftance from 
the top of the fnout, by which mark it is diftin- 
guilhed from the coregoni; and the teeth are 
large, and arranged on the tongue, in the palate, 
and in the jaws. Artedi enumerates two fpecies. 
OSPREY; the Falco Halisetus of Lihn£eus. 
Some naturalifts have confidered this bird as a 
fpecies of falcon, and others as a fpecies of eagle. 
It feems, however, properly to belong to the 
aquiline kind. It frequents rivers, lakes, and 
the fea-ftiores; builds it's neft on the ground, 
among reeds ; lays three or four white eggs, ra- 
ther lefs than thofe of a hen; and chiefly fiibfifts 
on fifti, precipitating itfelf on them from the {ky. 
The Italians compare the violent defcent of this 
bird on it's prey to the fall of lead into the waters 
and hence call it the leaden eagle. 
The Ofprey is about two feet long; and the ex- 
panfion of it's wings is upwards of five feet. The 
wing, when clofed, reaches beyond the end of the 
tail, which confifts of twelve feathers, the two 
middlemoft of which are duflcy, and the others 
barred alternately on their inner webs with brown 
and white. The quill-feathers of the wings arc 
black ; and the fecondary feathers with the coverts 
are dufl<y, the former having their interior webs 
varied with brown and white. The head is fmall 
and 
