30 
O S T R E 
71. Oftrea fauciata: fhell white, with purple fpots, 
and numerous unequal rays ; the margin crenate. Found 
in the Red Sea. 
72. Oftrea crenulata: fliell oblong, with undulate rays 
and ftriae, and tranfverfe interrupted bands ; margin cre- 
nulate. This is a very fmall fpecies. 
73. Oftrea innominata: fliell roundifh, fpotted, with 
deep grooves very finely ftriate tranfverfely ; margin cre- 
nulate. One of the ears hardly vilible. 
74.. Oftrea rufefcens : fliell roundifn, pale rufous, with 
twenty-four rays ; the ears with decuflate ftriae. 
75. Oftrea fquamata : fliell roundifh, with thick rays, 
furnifhed with diftant parallel fcales, and prickly at the 
fid^s. The fliell is convex and fpotted ; the margin cre¬ 
nate. 
76. Oftrea anonyma : fhell rather oblong, with narrow 
fcaly ray's, the interftices broader and ftriate perpendicu¬ 
larly ; ears with perpendicular wrinkles. The fliell is 
varied with angular lines and fpots. 
77. Oftrea decem-radiata: (hell flattened, with ten 
fmooth flat unequal rays ; ears tranfverfely ftriate. 
78. Oftrea tenuis : fhell thin, with deprefied fcaly rays ; 
ears fhort. It is found in India and the North Seas. The 
fhell is bay, or cinereous fpotted with black; fometimes 
white or carmine, or pale-orange. 
79. Oftrea valentii : fhell with twenty rays, and tranf¬ 
verfe femilunar bands. It is found in India. The fhell 
is red ; it refembles the O. maxima, but the ears are un¬ 
equal. 
80. Oftrea media: fhell fomewhat oblong, with crowded 
raj's. Shell middle-fized, reddifh, faffron, or piceous. 
81. Oftrea crocea : fliell faffron, with muricate fcaly 
rays alternately lefs. 
82. Oftrea fiorida : fhell roundifh, white, with rofy fpots. 
83. Oftrea ochroleuca: fliell oblong, ochraceous, with 
rays fmooth on one part, and granulate on the other. 
84. Oftrea muftelina : fhell pale-tawny, with yellow 
fpots and bands, and fmooth rays ; ears tranfverfely ftriate. 
The fhell is two inches and a quarter long, and about as 
much broad. 
85. Oftrea flammea: fliell faffron, rather oblong, with 
very fine perpendicular ftriae. 
86. Oftrea incarnata : fliell rather oblong, flefli-colour, 
with interrupted red bands and flattened rays. 
87. Oftrea guttata: fliell yellowifh, rounded, dotted 
with red, with rays unequally converging at the hinge. 
88. Oftrea depreffa : fliell ochraceous, with flat bifid 
rays. The fhell is about an inch long, and fomenting 
broader. 
89. Oftrea regia ; fliell roundifh, deep-red, with rounded 
rays. The ear of the lower valve deeply ernarginate. 
90. Oftrea paliiata: fliell equivalve, with numerous 
fmooth rays. It refembles O. pallium, but is lefs rough, 
and has fewer rays; fhell ftraw-colour, with purple un¬ 
dulate bands. 
91. Oftrea feminuda : fliell orange, oblong, muricate, 
with fcales as far as the middle ; with twenty-two rays. 
The fliell is one inch and three quarters long, and one 
inch and a quarter broad ; ears with very fine fcales. 
92. Oftrea modefta : fliell roundifh, hoary, withbrown- 
ifli, reddifh, and bluifh, fpots ; fpaces between the rays 
broad. The fhell lias two filiform bands at the hinge. 
93. Oftrea principalis : fhell purple, with a brown 
margin ; the rays fcaly from the middle, and fmooth ac 
the hinge. 
94. Oftrea verficolor: fliell variegated, with peftinate 
fmooth rays. 
3. Valves more gibbous on one fide. 
95. Oftrea flavicans : fliell nearly equivalve, with eight 
ftriate rays, the margin rounded on one fide. It is found 
in the South Seas. The fliell is rather oblique ; white va¬ 
ried with brown and red, within white ; the rays yellow ; 
one of the ears very fliort. 
96. Oftrea fafeiata ; fhell equivalve, with twenty rough 
A. 
rays, the interftices ftriate; ears equal, fmall. Inhabit* 
the American and Atlantic Seas. The fhell is white, 
pellucid, gaping each fide, very finely ftriate within ; the 
margin crenate. 
97. Oftrea fragilis: fliell equivalve, with twenty-five 
rays; margin very entire ; ears acute. Inhabits the Ni- 
cobar-iflands ; refembles the laft, but is flatter, and has 
more rays ; fhell thin, brittle, one inch and a quarter 
long, and about halfas broad. 
98. Oftrea lima : fliell equivalve, with twenty-two im¬ 
bricate fcaly rays, rounded at one margin ; ears oblite¬ 
rated. It is found in the Mediterranean, Indian, and 
Red, feas. The fliell is three inches long, and two 
inches and a quarter broad ; white and rather flat; the 
fcales elevated and acute ; ears wrinkled. 
99. Oftrea glacialis : fliell equivalve, with fifty imbri¬ 
cate interrupted rays; ears equal, one of them unequally 
plaited. It is found in the American Ocean ; refembles 
the laft, but has more numerous rays ; fhell fnowy, with 
a crenate margin ; another variety lias the margin entire. 
100. Oftrea hians : fhell whitifh, thin, gaping each fide 
and oblique, with obfolete undulate rays, and tranfverfe 
rounded femilunar ftriae. Inhabits Norway ; is one inch 
and a half long, and three-quarters of an inch broad ; ears 
very fmall and acute; margin crenate, very entire within. 
iot. Oftrea excavata : fliell dirty-white, with longitu¬ 
dinal undulate ftriae, and a few tranfverfe rings, fmooth 
within ; one ear obfolete ; margin very entire. It is found 
in Norway, but is rare ; five inches long, and three and a 
quarter broad. 
II. Oysters. Itoug/t, and generally plaited on the outftde. 
102. Oftrea malleus: fhell equivalve, three-lobed, two 
of the lobes placed tranfverfely, like the head of a ham¬ 
mer. This fpecies is found in the deep parts of the In¬ 
dian and South Seas, and is very rare. Shell about fix 
inches long, and four inches and three quarters broad ; 
black with a dark-blue caft, gaping, formed like a crofs ; 
the valves lamellate. 
103. Oftrea valfella: fhell fubpellucid, narrow, elon¬ 
gated, brittle, lamellate; one end rounded; within very 
lmooth and glolfy. It inhabits the Red Sea ; is three 
inches and a half long, and one broad. The fhell is vio¬ 
let, tawny, or ferruginous, gaping at the hinge ; rough 
on the outlide, and thinner at the rounded end. 
104. Oftrea anatinaj fhell pellucid, lamellate, and la¬ 
terally incurved. It inhabits the Nicobar iflands ; about 
an inch broad, and, including the curvature, three inches 
long ; its fhape in fome meafure refembles a duck when 
fitting; fhell thin, brittle, varied with white and violet. 
105. Oftrea diluviana : fliell plaited on the outfide ; the 
margin with ererit acutangular teeth. This is found in a 
foflil ftate in the calcareous mountains of Sweden, about 
the fize of a common oyfter; the margin with ere£t ferra- 
tures, formed as it were of the imbricate lamellae of the 
fhell, and tranfverfely ftriate; valves with pe&inate 
plaits and acute wrinkles. 
106. Oftrea folium : fliell ovate, obtufely plaited at the 
fides, paralitical. It inhabits the Indian Ocean, where it 
is frequently found adhering to Gorgonia; fhell ftraw- 
colour, pale-tawny, or violet, within filvery; hinge with 
a triangular hollow ; upper valve turgid on the back 
towards the middle, wrinkled each fide, and tranfyerfely 
ribbed ; lower valve lefs, flatter, and grooved in the middle. 
107. Oftrea orbicularis : fliell orbicular, flat, with an 
entire crenate margin. Shell with a very obtufe margin, 
about the fize of the end-joint of the thumb. 
108. Oftrea edulis, the common oyfter: fhell nearly or¬ 
bicular and rugged, with undulate imbricate fcales ; one 
valve is flat and very entire. There are fix varieties of 
this fpecies, found in different parts of the European and 
Indian Seas, affixed to rocks, or in large beds. The fliell 
is of various fixes, forms, and colours, within while, and 
often gloffy, like mother-of-pearl. It was formerly 
thought to have no power of locomotion ; but it is now 
ascertained. 
