700 NATURAL HISTORY OF AQUATIC ANIMALS. 



many plantations in the Gulf States, the Conch is perforated at the apex of the spire, and forms 

 a. horn, used to call workmen in from the fields and at dinner. From fragments of this great 

 inollnsk, also, the Indians of Florida and the Antilles made their most esteemed beads and 

 pendants. Cabeza de Vaca says that the columella of large Conchs were chiefly available for this 

 purpose. "These beads are more or less cylindrical or globular, and always drilled lengthwise. 

 Some are tapering at both ends, resembling a cigar iu shape, and were two and one-half inches in 

 length. The aborigines also made . . . peculiar pin-shaped articles consisting of a more or 

 less massive stem which terminates iu a round knob." 



The Strombus enters, when ground, into the manufacture of porcelain; is extensively burned 

 for lime; and is carefully calcined for medicinal purposes. There is also derived from it a 

 secondary product of great value the conch-pearl. When perfect, this pearl is described as either 

 round or egg-shaped and somewhat larger than a pea, of a beautiful rose color, and watered, that 

 is, presenting, when held to the light, the sheeny, wavy appearance of watered silk. It is 

 however, very rare to find a pearl which possesses all the requirements that constitute a perfect- 

 gem, and such proves an exceedingly valuable prize. Although many of these pearls are annually 

 obtained by the fishermen in the Bahamas, not more than one in twenty proves to be a really 

 good gem. Pink is the most common and only desirable color, although white, yellow, and brown 

 pearls are occasionally found. Even among the piuk ones there is usually some defect which mars 

 their beauty and materially injures them ; some are very irregular in shape and covered apparently 

 with knobs or protuberances; others are too small, while many lack the watering which gives 

 them their great value and chief beauty. Most of the conch-pearls have been sent to London, 

 and the demand for them is increasing; a few come to New York. 



Lunatia heros is very conspicuous along our coast, from the Gulf of Saint Lawrence to Cape 

 Hatteras or beyond, wherever sandy shores and pure waters are to be found, and it is abundant 

 and of very large size on the outer beaches of the coast of New Jersey. "When in motion the 

 white soft parts are protruded from the shell to a remarkable extent and spread out broadly on 

 all sides, so as nearly to conceal the shell; "the foot is large, flat, and broadly expanded, with thin 

 edges, and by means of it the animal is able to burrow, like a mole, beneath the surface of the 

 sand." This Snail, like many others of its tribe, drills round holes through the sides of various 

 bivalve shells by means of the small flinty teeth on its ribbon-like tongue, which acts like a rasp, 

 and having thus made an opening it inserts its proboscis and sucks out the contents. All sorts of 

 burrowing bivalves in this way fall victims to this and its close ally, the Neverita diiplicfita. "Nor 

 do they confine themselves to bivalves, but will drill any unfortunate Gasteropods they may happen 

 to meet, not even sparing their own young." Their usual haunts are away from the oyster-beds, 

 however, so that, although they are a familiar sight in the dredge, the harm they do to this 

 industry is of small account. 



Following this in the list come various small shells, such as those of the genera Littorina^ 

 Rissoa, Melampus, and Bittitim, of which it can only be said that they serve a very useful purpose as 

 scavengers, swarming upon the mud exposed at low tide and greedily devouring carrion of fishes, 

 etc., which would otherwise decay and pollute both air and water. The same good service is done 

 by the small mollusks previously noticed as "Borers," and many following. 



This brings us to the beautiful family of Abalones, Ormer-shells, or Sea-ears, in which there is 

 a very large trade on the Pacific coast, under the industry of the Chinese there, to which will be 

 given a special chapter. 



In the Limpets (Crepidtila and Acmcn) the oystermen consider they have a friend, since when 

 they see these clustering upon thtir planted beds they look forward to a profitable harvest the 



