OSTREA. 
pearl. The old thells have frequently an Anomia (which 
fee) fixed to them, and ate fometimes covered ge ferpulz, 
lepades, fertulariz, and other marine prodution The oyf- 
ter is fuppofed by naturalifts.to be an hecaapheodite ani 
The {pawn which they caft in May adheres to the rocks, and 
other fubftances at the bottom of the fea, and the fhell is 
faid to be formed in the fpace of 24 hours. 
thought to have no power o locomotion, but it 
afcertained, by accurate obfervation, that it can-move fro 
place to place, and vary its habits according to creauiianes 
Oyfters which are recently taken up aces that are 
left dry by the fea open ee thell, lo fe t 
ept in refervoirs, in whi 
the ae se ofed to the’ rye of 
rbed in mes beds, 
he oytter. 
taceous animals, as mvfcles, {callops, ftar-fifh, and crabs, are 
their moft deftru€tive enemies. 
Oyfters are of different colours in different places; in 
Spain they are found of a red and ruffet colour; in 
Illyria they are brown, but the fifh is black, and in the 
Red fea of the colour of the rainbow. ‘The green oytter, 
Dieppe. 
oa 
Co) 
where sag are eaten raw or 
Britain has long been ae for its oyfters ; and the an- 
cient Romans, who were ex 7 vac! fond of this fifh, had 
their layers or ftews for oyfters as we have at prefent. 
conftru& them for the purpofe of indulging his appetite, but 
for the fake of the profit attached to t This country 
ftill retains its fuperiority in sar vein over other countries. 
our coafts produce them naturally, and in fach 
places they are taken by Drepaine, (which fee,) and are 
a confiderable article of commerce, in the raw and pickled 
t 8 or layers o 
nature never allotted as aay sane for them. Thofe ne 
Colchefter have long bee e oyfters or {pat 
are brought to convenient plcer ee they improve in tafte 
and fize. See Mitton. 
SEMIAURATA, Shell oval, tightly eared, fmooth, with 
an oblique bafe. It inhabits the Mediterranean, is about 
1% inch long, and 1 broad; of a dirty olive, with a few 
undulate white lines; very thin n; each valve convex and 
ending in a beak ; hinge with five rounded hollows. 
TRIATA, Shell oval, with longitudinal filiform ridges ; 
infide green. It is found in European feas, and is about 
aninch in diameter. The fhell is thick, ftrong, nearly 
opaque, not membranous, as in the commen oyiter, with 
numerous flender aes ridges, divided towards the cee 
valve flatti 
ORNICATA. Shells rough, oblong, raed with divergent 
hinges, vaultedinternally. It 1s found in the Red fea. The 
fhell is brittle, membranaceous, tawny, about as long asa 
finger, terminating at the hinge in an elongated acutangular 
SINENSIS. a rough, lamellate, eae and glabrous 
within; lower valve larger, concave, and ending in a beak, 
with ten obtufe ona, It is found o cae Chine’e thore S53 
four inches long, and a little pei g fhell ruffet- eon, 
within whitifh towards the hin 
SPONDILOIDEA. Shell equivalve, eek oe oval, 
beaked, glabrous, with perpendicular, undulate, granulate 
ftrie on the upper valve; margin very far Inhabits 
India: three inches two lines long, - inches five lines 
broad; fhell white, with a few tawny fj 
ForsKAHLuU. Shell plaited, and acting in a long 
incurved hollow beak; the middle ribs with imbricate 
ll with longitudinal wrinkled ‘plaits ; 
lower valve a little lefs and flatter. It inhabits the 
ents and Mediterranean feas. Varies very much in fhape 
and fize; but is generally cinereous, with a mixture of 
Soe fometimes white, with red or blueifh ftreaks. 
hell pee equivalve, ao ee ‘amel- 
lous; one valve with a a a is found in the 
American and India ae long and four 
broad ; a or eas ‘vithin cist ite. 
ORNUCOPIAZ. Upper valve flat, lower one hollow and 
bide aie with {cales, wrinkles and plaits, and ending in 
oe ted beak. It is found in the vudian and African 
VIRGINICA. 
oce 
Paani: Shell thin; lower valve convex and thicker, 
the other flat. It inhabits the Indian and Atlantic feas, and 
fixes itfelf to the roots and ftumps of trees growing clare to 
and hanging over the water, efpecially the Mangifera ; varies 
in form and fize, but 1s often as large as the palm of the 
and, 
Exa.Bippa. Shell thin, the upper valve longer and 
more convex. is is found in the Adriatic, fixed to other 
fhells, fometimes alone, fometimes feveral together ; about 
one inch and a half long, but is variable as to fhape and 
cn generally whitith, rarely yellow or violet. 
A 
Se a a black {pots ; hinge with a broad conic tooth in 
the a 
NEGALENSIS. Shell equivalve, roundifh, fmooth, flat. 
It Geen the Jhores of Senegal, adheres to rocks; 
about two inches in diameter; tawny, within whitifh. 
STELLATA. Shell thin, depreffed, rough, unequal ; 
upper valve ribbed, the ribs with a few {pines. It is found 
in Guinea fometimes affixed to other bodies by the hinge ; 
fometimes 
