UTILIZATION OP ABALQNE SHELLS. 225 



where a lialiotis had been attacked by another mollusk — a boring bivalve 

 known as Navea which had cut its way through the shell. Advised of 

 this enemy, the haliotis had defended itself by adding coating upon 

 coating of nacre as a bulwark between him and his foe, until, as the 

 JVavea progressed, a large knob was built in the interior of the abalone's 

 shell. 



The shells are usually sent to San Francisco from the lower counties 

 of California in the rough, and are the means of considerable speculation 

 among coasting captains. The price paid for them by merchants varies 

 greatly ; an average at present would be $50 or $60 a ton. From San 

 Francisco they are shipped both to China and to the Eastern States. In 

 China they are broken up and used for inlaying in connection with the 

 lacquer-work for which the Chinese are famous. The mosaics of Europe 

 are often adorned by the same means, and various arts are served by their 

 glittering fragments. It was with pieces of this sort of shell that those 

 wonderfully beautiful inlaid screens from Holland, representing moon- 

 light landscapes, etc., which attracted so much attention at the Centennial 

 Exhibition, were produced. 



Many of our shells are sent to Europe, there to be polished with the 

 help of acids until they shall be as lustrous outwardly as inside, and then 

 are reshipped to the United States to serve as mantel ornaments, soap- 

 basins, match-boxes, card-cases, receptacles for flowers, etc. The same 

 work is done to some extent in San Francisco, and many are there manu- 

 factured into gold-mounted ear-rings and brooches, shawl-pins, and various 

 toilet articles, particularly ladies' high hair-coinbs of great costliness, if 

 not invariably of equal elegance. 



One dealer, also, at San Diego, California, polishes these shells him- 

 self, and sells them to tourists for from twenty-five cents to five dollars, 

 or sends them to the East by mail in " nests " of four to six. The young 

 of one sort are cleaned with the aid of hydrochloric acid, but the usual 

 method with aged shells is to grind away the epidermis by hand by rub- 

 bing upon stones. It is too delicate work to trust to machinery, lest holes 

 should be made in the thin pearly underlayers. 



A peculiarity of haliotis shells is the line of four to ten round holes 

 along the ridge at one side. It is through these apertures that the mol- 

 lusk gets the fresh water necessary to its breathing when it sits close 

 down upon a rock, and when none can flow in under the edges of the 

 tio-ht shell. A similar provision exists in the "key-hole" of the limpet, 

 and in the " notch " in the shelly lip of a large number of whorled shells, 

 like the whelk, conch, etc. Through these holes, when the animal is 



15 



