346 THE LIMA, OR FILE-SHELL. 
to grow in the open seas ; but their artificial size is said to be a poor compensation for their 
comparative want of flavor, the artificially bred Oyster being to the marine mollusk what the 
capon is to the pheasant. 
In the sea, thousands of Oysters perish by the attacks of a strange enemy. The reader 
has doubtlessly remarked that the shells of many Oysters are partially perforated by little 
round holes. These are the marks left by a kind of sponge, called Cliona, which burrows 
into and gradually destroys the shells of this mollusk, causing them to fall to pieces by its 
ravages. 
Asa matter of economic value, the Virginia Oyster and the common Clam are all important. 
The Vrrernia Oyster (Ostrea virginiana) extends along our coast from the St. Lawrence 
River to the Gulf of Mexico. Many years since Oysters were natural to the shores of New 
England. Old extinct beds are found around Cape Cod, and along the coast to Mount Desert. 
Huge heaps of shells are seen at various places—notably in Casco Bay, Maine. They are of 
enormous size. Professor Verrill inclines to the opinion that climatic changes have conspired 
to produce a scarcity, and, in some places, extinction of Oysters in New England. South of 
Cape Cod they flourish abundantly. In the Oyster of our shores the sexes are separate ; the 
eges are fertilized after they are deposited, and develop in the water. At first the young 
Oyster swims freely, and after the shell begins to develop it settles permanently. Our Oysters 
are all of one species, notwithstanding several specific names have from time to time been used 
to designate them. Two species of Oysters are edible on the Pacific coast, O. conchophila and 
O. lurida. The European Oysters are insufficient to supply the market, and the American 
Oysters are imported there in great quantities. Edible Oysters are found in Japan, Cape of 
Good Hope, and in Australia. Some of the Asiatic ones measure three feet in length. 
The Oyster industry in America exhibits the following statistics: The Census of 1880 
gives the number of persons employed in the business as over fifty thousand, and over four 
thousand vessels ; involving an investment of ten million dollars. The number of bushels of 
Oysters sold is over twenty millions. 
A curtous and rather valuable shell is the CHtNESE WiNbDoW-sHELL. It is found in the 
country from which it takes its name. 
This shell is extremely flat, and of a beautiful translucence, and in many parts of China is 
employed for windows, just as is ground-glass among ourselves, the nacreous substance per- 
mitting the light to pass through, but effectually preventing an inquisitive eye from distin- 
guishing objects within the apartment. Very small pearls are found in this shell, too minute 
and too opaque to be employed by jewellers. They are, however, collected and exported to 
India, where they are calcined and formed into lime for the use of wealthy betel-chewers. 
They are also burned in the mouths of the dead. 
The shell is of great use in commerce, affording the substance from which is cut those 
large flat ‘pearl’? buttons that were formerly so fashionable, but seem now to have descended 
to the denizens of the stable. The button ‘‘moulds”’ are cut from the shell by an instrument 
that somewhat resembles the trephine, by which portions of the skull are removed in case of 
severe injuries, and in their rough state look like gun-wads. They then pass through a series 
of processes in which they are polished and pierced, and made ready for sale. 
THE SADDLE-SHELL is remarkable for the way in which the shell is attached to other 
substances. The contrivance by which it is attached is most remarkable. The animal deposits 
a plug or peg of shelly matter on the oyster, and in the right valve there is a hole or notch 
into which the peg fits, much after the fashion of a button. When the left valve is in its 
place, this contrivance is bidden. The shell of this creature is beautifully 
thicker, indeed, than the paper on which this account is printed—and elegantly waved. It 
inhabits the European seas. 

Tue Lima, or Fine-suEnt, of the same species, is worthy of notice on account of the 
curious refuge which it constructs by binding together a large mass of shells, corals, sand, and 
