O S T 
large quantity of moifture ; lay them again in the fun till 
perfectly dried; and then finifh the powdering them, and 
lift the powder through a fine lieve. Give twenty or thirty 
grains of this powder every morning, and continue it 
three weeks or a month.” Mem. Acad. Par. 1700. 
Oyfters are often found in a fofiil ftate ; as to which, 
fee Ostracites, p. 27 of this volume; but more parti¬ 
cularly the article Conchology, vol. v. p. 31. 
109. Oftrea femi-aurata: fliell oval, (lightly eared, 
fmooth, with an oblique bafe. It inhabits the Mediter¬ 
ranean ; is about one inch and a half long, and one and 
a quarter broad ; of a dirty-olive, with a few undu¬ 
late white lines ; very thin ; each valve convex and end¬ 
ing in a beak ; hinge with five rounded hollows. 
no. Oftrea ftriata: fliell oval, with longitudinal fili¬ 
form ridges ; infide green. It is found in European feas, 
and is about an inch in diameter. The (hell is thick, 
ftrong, nearly opaque, not membranous, as in the com¬ 
mon oyfter, with numerous (lender irregular ridges, di¬ 
vided towards the bottom ; upper valve flattift), lower 
concave ; hinge broad, deep, fomewhat triangular, and 
ftriate tranfverfely. In many (hells is a white radiate 
mark below the hinge, formed by the cartilage of the 
fifti. 
in. Oftrea fornicata: fliell rough, oblong, linear, with 
divergent hinges, vaulted internally. It is found in the 
Red Sea. The fliell is brittle, membranaceous, tawny, 
about as long as a finger, terminating at the hinge in an 
elongated acutangular beak. 
112. Oftrea Sinenfis: (hell rough, lamellate, unequal, 
and glabrous within ; lower valve larger, concave, and 
ending in a beak, with ten obtul'e plaits. It is found on 
the Chinefe fliores ; four inches long, and a little nar¬ 
rowed ; fliell ruflet-brown, within whitifli towards the 
hinge. 
113. Oftrea fpondiloidea: fliell equivalve, pellucid, 
flattened, oval, beaked, glabrous, with perpendicular, 
undulate, granulate, ftriae on the upper valve ; margin 
very (harp. Inhabits India: three inches two lines long, 
two inches five lines broad ; fliell white, with a few tawny- 
fpots. 
114. Oftrea Forlkahlii: fliell plaited, and terminating 
in a long incurved hollow beak ; the middle ribs with 
imbricate fpinous wrinkles; the other valve flat. It is 
found in the Red Sea. Two inches three lines long, and 
about an inch broad ; the flat valve whitifli, the other 
nearly violet. 
115. Oftrea plicatula : fliell with longitudinal wrinkled 
plaits ; the lower valve a little lefs, and flatter. It inha¬ 
bits the American and Mediterranean Seas. Varies very 
much in fliape and colour. 
116. Oftrea roftrata: fliell oblong, rugged; the upper 
valve lamellate, with a denticulate margin, the other ex¬ 
cavated and longitudinally grooved; beak prominent. 
It inhabits the Mediterranean. Upper valve yellowifti, 
green, the other violet, varied with white ; within cre¬ 
taceous, or clialky-white. 
117. Oftrea Virginica: fliell nearly equivalve, thick, 
rough, lamellous ; one valve with a prominent beak. It 
is found in the American and Indian Oceans ; nine inches 
long and four broad. 
118. Oftrea cornucopias: upper valve flat, lower one 
hollow and ftriate, rough with fcaies, wrinkles, and plaits, 
and ending in an elongated beak. It is found in the In¬ 
dian and African Oceans. 
119. Oftrea paralitica: fliell thin; lower valve convex 
and thicker, the other flat. It inhabits the Indian and 
Atlantic Seas, and fixes itfelf to the roots and flumps of 
trees growing clofe to, and hanging over, the water, efpe- 
cially the Mangifera; varies in form and fize, but is often 
as large as the palm of the hand. 
120. Oftrea exalbida: (hell thin, the upper valve 
longer and more convex. This is found in the Adriatic, 
fixed to other (hells, fometimes alone, fometimes feveral 
together; about one inch and a half long, but is variable 
REA. 35 
as to fliape and fize ; generally whitifli, rarely yellow or 
violet. 
121. Oftrea criftata: fliell rugged, with imbricate la¬ 
mellae ; the margin with obtufely-plaited teeth ; the beak 
of one valve protruded. Shell an inch long, and ten lines 
broad 5 white, with a few black fpots ; hinge with a broad 
conic tooth in the middle. 
122. Oftrea Senegalenfis: fliell equivalve, roundifli, 
fmooth, flat. It inhabits the fliores of Senegal, and ad¬ 
heres to rocks ; about two inches in diameter. 
123. Oftrea ftellata: fliell thin, deprefled, rough, un¬ 
equal ; the upper valve ribbed, the ribs with afewfpines. 
It is found in Guinea, fometimes affixed to other bodies 
by the hinge; fometimes round, fometimes oblong; 
very thin, white, with red orbluifli marks. 
124. Oftrea ovalis : fliell oval, very thin, and termi¬ 
nating in afliort acute lateral channelled beak; with ob- 
folete, unequal, perpendicular, ftriae. The (hell is about 
an inch long, brittle, whitifli, within glofly iilver-white ; 
lower valve exceeding the upper both in length and 
breadth. 
125. Oftrea papyracea : (hell roundifli, fnowy, very 
thin, pellucid ; upper valve terminating in a fliort acute 
beak. It is found firmly fixed with the Lepas tintinna* 
bulum, 
126. Oftrea annulata : fliell equivalve, orbicular, white, 
with concentric femicircles. It is found in the North Seas. 
127. Oftrea retufa : fliell equivalve, oblong, white, gla¬ 
brous, ftriate ; with an umbo or knob remote from the 
hinge. This is alfo found in the North Seas. 
III. Hinge with a perpendicular grooved line. 
128. Oftrea perna : fliell equivalve, obovate, unequal, 
rounder dt one end. 
129. Oftrea ifognomum : fliell equivalve, with a larger 
lobe, nearly forming a right angle with the hinge. There 
are four varieties of this fpecies. They are found in the 
Indian Ocean and South Sea ; from five to fix inches long, 
and about one inch and three quarters broad in the mid¬ 
dle ; fliell black, with a violet mixture, and pearly with¬ 
in ; lamellate, with an open beak. A very rare fliell. 
130. Oftrea ephippium: fliell equivalve, orbicular, 
comprefled, membranaceous. Found in the Indian Ocean 
and at the Cape of Good Hope ; very rare. The (hell is 
about five inches long, and five and a half broad ; black- 
ifti, ferruginous, or purplilli, and pearly within ; roundifli, 
lamellate, with a very acute margin. 
131. Oftrea pifta: fliell equivalve, thin, pellucid, and 
pointed at the hinge, the other end dilated ; margin very 
acute. It inhabits the Red Sea; is more than an inch 
broad, and about two long ; yellowifti-brown, with paler 
undulate rays. 
132. Oftrea legumen : fliell flat, hoary, thin, pellucid, 
lamellate ; hinge with an oblique line ; the interftices of 
the grooves black. This fpecies inhabits the Nicobar 
Iflands ; is four lines broad, and above two inches long ; 
near the knob is a livid fpot. 
133. Oftrea alata: fliell flat, brittle, pellucid, and di¬ 
lated towards the margin; hinge with an oblique line 
ending in a fmall beak. It is found in America. 
134. Oftrea mytiloides : fliell nearly equivalve, ovate, 
ventricofe, ftraight. It is found in a foflil ftate in Alface. 
135. Oftrea torta : fliell equivalve, intorted. This alfo 
is found foflil in Alface. 
136. Oftrea pes-lutrae : fliell equivalve, fmooth, wedge- 
fhaped, with fix obtufe plaits; varied with purplifh and 
white, and marked with very fine longitudinal ftriae; the 
margin (lightly fcalloped. 
OSTRICO'NI, a river of the ifland of Ccrfica, which 
runs into the fea near the town of Oftriconi, 
OSTRICO'NI, a town of the ifland of Corfica : twen¬ 
ty-two miles weft-fouth-wefl: of Baftia. 
OSTRIF'EROUS, adj. [from the Lat. oftrea, an oyfter, 
and fero, to bear.] Producing oyfters ; bearing oyfters. 
Cole, 
OS'TRINGER. 
