12 



INTRODUCTORY CHAPTER. 



Although, at the first glance, the inhabitants of shells 

 appear to be beings of a very uninteresting nature, a 

 due consideration of the valuable properties of many, 

 and the usefulness of all, will enable us to perceive, that, 

 regarding them merely in an interested point of view, 

 they are worthy of the strictest attention of the natu- 

 ralist. In the first place, the whole of them afford food 

 for the different species of fish, and other inhabitants 

 of the deep. The Tyrian dye, the royal purple of the 

 ancients, was produced by the inhabitant of a small 

 univalve shell, of the genus Purpura. That beautiful 

 ornament in dress, the oriental pearl, is the consequence 

 of disease in a species of mussel, and the inner por- 

 tion of the shell of the same animal, is the well-known 

 substance, mother-of-pearl A kind of silk is obtained 

 from the beard of the pinna, which, in some places, is 

 made into gloves. As an article of food we may men- 

 tion the well-known oyster, the mussel, scallop, &c,, and 

 some of the larger kinds form no small portion of the 

 subsistence of the natives of the South-Sea Islands, and 

 the Negro population in the West Indies. 



The Teredo navalis, or ship-worm, has, by its de- 

 structive powers, ruined the noblest vessels, and rendered 

 useless the timbers, on which many of the constructions 

 in harbours mainly depend for security; on this account 

 great attention has been bestowed on its natural history 

 and habits. The barnacle, which attaches itself to the 

 bottoms of ships, renders the planks so foul, as to inter- 

 fere materially with the rate of sailing of the vessel itself. 

 These are only a few of the useful and noxious qualities 

 of these inhabitants of the deep. 



The shell with which a Molluscous animal is covered. 



