BIVALVES. Al 
of the tropical regions, extend even to the unassuming 
oyster. Many of the species are beautifully shaded, 
and the shells of such as inhabit the Red Sea are 
tinted with the vivid colours of the rainbow. 
The last division contains the O. Edulis, or common 
Oyster, which is too well known for its nutritive and 
palatable qualities to render any description necessary. 
The old shells are often covered with various adhe- 
sions, such as Anomie, or Antique Lamps; Serpule, 
and Lepades, or Sea-Acorns; Serpularie, and other 
marine productions. The interior has generally a 
pearly appearance, and some specimens have been 
found containing pearls. 
Varieties of this interesting genus are met with 
on the shores, and in the depths of almost every 
ocean, either in clusters, or else affixed to the rocks. 
Pilgrims gathered the shells of the O. Jacobe@a along 
the shores of Palestine, and placed them in their 
hats, as emblems that they had crossed the sea, in 
their way to the Holy Land, or some distant object 
of devotion. Hence they are still preserved in the 
armorial bearings of several distinguished families. 
He who muses on the muddy, flat, and desolate 
shores of Hudson Bay, may observe, for the space of 
at least ten miles, large numbers of the common 
species deposited upon the beach. They tell him of 
other days and other times, when the waters yielding 
