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. 



As a matter of economic value, the Virginia Oyster and the common Clam are all important. 



The Virginia Oysteh {<>sl,;<t rirginiana) 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 

 eggs 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, 0. concTiopMla and 

 0. 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 

 Grood 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 cttrtous and rather valuable shell is the Chinese Window-shell. It is found in the 

 country from which it takes its name. 



This shell is extremely Hat, 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 Mat '-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 hidden. The shell of this creature is beautifully thin— hardly 

 thicker, indeed, than the paper on which this account is printed— and elegantly waved. It 

 inhabits the European seas. 



The Lima, or File-shell, 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 



