4*6 CONCH 
fammea. 85. 0. faffron-coloured, oblong, with fine perpendi- 
cular ftriae ; very minute. 
incarnata. 86. O. oblong, flelh-coloured, with interrupted red 
bands; and flattened rays. 
guttata. 87. O. yellowifh, rounded, dotted with red ; rays 
unequally converging at the hinge. 
depreffta. 88. O. ochraceous, with flat bifid rays ; 1 inch 
long. 
regia. 89. O. roundifh, deep-red, with rounded rays. 
palliata. 90. O. equivalve, with numerous fmooth rays : is 
lefs round, and has fewer rays, than qftrea pallium, 
feminuda. 91. O. orange, oblong, muricated, with fcales as far 
as the middle ; rays 22 ; i^-inch long, 14 broad. 
modejla. 92. O. roundifh, hoary, with brownifh, reddifh, and 
bluifh fpots ; interftices of the rays b.oad ; 2 filiform 
bands at the hinge. 
principalis. 93. O. purple, with a brown margin ; rays fcaly from 
the middle, and fmooth at the hinge. 
verjicolor. 94. O. variegated, with peflinated fmooth rays. 
c. Valves more gibbous on one Jide. 
favicons. 95. O. nearly equivalve, with 8 ftriated rays : mar- 
gin rounded on one fide. South fea. 
fafciata. 96. O. equivalve, with 20 rough rays; interftices 
ftriated; ears equal, fmall. Atlantic feas. 
fragilis. 97. O. equivalve, with 25 rays; margin very entire ; 
ears acute ; 1 4 inch long. Nicobar iflands. 
lima. 98. O. equivalve, with 22 imbricated fcaly rays, 
rounded at one margin ; ears obliterated ; 3 inches 
long, 2' broad. Mediterranean and Indian feas. 
glacialis. 99. O. with 50 imbricated, interrupted rays; ears 
equal ; one of them unequally plaited. American o- 
cean. 
hians. 100. O. whitifh, thin, gaping on each fide, and ob- 
lique, with obfolete, undulated rays, and tranfverfe, 
rounded, femilunar ftriae ; i-§- inch long, ^ broad. Nor- 
way. 
excavata. 101. O. dirty white, with longitudinal, undulated 
ftriae, and a few tranfverfe rings ; one ear obfolete ; 
margin entire ; 5 inches long 3^ broad. Norway. 
B. Rough , and generally plaited on the outfde. OTSTEBS. 
malleus. jo 2. O. equivalve, 3-lobed, 2 of them placed tranf- 
verfely like the head of a hammer ; 6 inches long, and 
4^ broad. Deep parts of the Indian and Southern 
oceans. Very rare. 
vulfella. 103. O. fub-pellucid, narrow, elongated, lamel- 
lated ; one end rounded ; 34- inches long, 1 broad. 
Red fea. 
anatina. 104. O. pellucid, lamellated, and laterally incurved; 
1 inch broad, and including the curvature, 3 inches 
long. Nicobar iflands. 
diluviana. 103. Q. plaited on the outfide ; margin with erefl, 
acute, angular teeth ; fize of a common oyfter ; found 
in a foflil ftate in the calcareous mountains of Sweden. 
folium. 106. O ovate, obtufely plaited at the fides ; para- 
fitical ; found adhering to gorgonia in the Indian 
ocean. 
orbicula- 107. O. orbicular, flat, with an entire crenated mar- 
ris. gin ; fize of the end joint of the thumb. 
edulis. 108. O. eatable or common oyjler ; orbicular and 
rugged, with undulated, imbricated fcales ; one valve 
flat, and very entire. European and Indian feas. — It 
is found, either in large beds, or adhering to rocks. 
The fhell is of various fize s, forms, and colours ; vvith- 
2 
O L O G Y. Chap, IV, 
in white, and often g.loffy, and of a pearly appearance. 
The old lhells have often an anomia fixed to them, and 
they are frequently covered with the ferpula and lepas, 
and the fertularia and other zoophytes. 
The common oyfter has been long know'n as a nu- Oyfters etn~ 
tritious food, and indeed in mod countries is greatly ployed as 
efteemed as a delicate luxury of the table. The oy-f'-od. 
fter is fuppofed by naturalifts to be a hermaphrodite 
animal. The fpawn which they caft in May, adheres 
to the rocks and other fubftances at the bottom of the 
fea ; and the fhell, it is fuppofed, is formed in the 
fpace of 24 hours, and which, according to fome, 
never leaves the fpot till removed by violence. But 
from the obfervations of M. Dicquemare, who has 
particularly ftudied the economy of the oyfter, it ap- 
pears that it poffeffes the power of moving from place 
to place, and that it varies its habits according to cir- 
cumftanees. Oyfters which are recently taken up from 
places which are left dry by the fea open their fhell, 
lofe their water, and die in a few days. But the 
fame oyfters kept in refervoirs, where they are left oc- 
cafionally by the fea, expofed te the rays of the fun, 
to fevere. cold, or are difturbed in their beds, acquire 
the habit of keeping the fhell clofe when they are un- 
covered with water, and exift without injury from this 
treatment for a long time. The oyfter fhould be frefh, 
tender, and moift. Thofe which are moft efteemed are 
caught at the mouths of rivers, and in clear water. 
The want of frefh water, it is faid, renders oyfters 
hard, bitter, and unpalatable. Mud and fea weeds 
are extremely injurious to the propagation and increafe 
of the oyfter. Other fhell fifh, and cruftaceous animals, 
as muffels, fcallops, ftar-fifh and crabs, are their moft 
deftrudlive enemies. „ 9 
Oyfters are of different colours in different-places: in Of different 
Spain they are found of a red and ruffet colour ; in Illy- kinds, 
ria brown, with the fifh black, and in the Red fea of the 
colour of the iris. The green oyfter, which is eaten in 
Paris, is brought from Dieppe. This colour is aferibed 
to the verdure which encompaffes the bed on which they 
are produced. The oyfters from Britanny in France, 
too, have been long famous ; but thofe which are brought 
from Marennes in Saintogne, are in higheft eftimation. 
The oyfters which are edged with a fmall brown fringe 
or beard, are generally preferred. Thefe are account- 
ed by the epicures fecundated oyfters. 
In tropical regions, the common oyfter is found at- Adhere to 
tached to trees. This affertion of the growth of oyf- trees in 
ters on trees has been often ranked among the exag- w'arm ds- 
gerated or groundlefs ftories of the marvellous travel- 
ler ; but this circumftance, when properly explained, 
will not appear different from the ufual economy of 
this teftaeecus animal. In warm climates where vege- 
tation is fo much more luxuriant than in northern lati- 
tudes, a great variety of plants, among which are feen 
large trees, grow on the fhores to the very edge of the 
fea ; and particularly on thofe places which are fhel- 
tered from the agitation of the waves. In fuch places, 
at the heads of bays and harbours, great abundance of 
mangrove trees grow up from the bottom, where it is 
feveral feet deep, covered with water. It is generally 
on the mangrove tree that the oyfter is found in the 
Weft Indies. Without the trouble of picking them 
from the trees, the branches growing under water to 
which they are attached, are cut off, carried home in 
balkets, 
mates. 
