ANIMAL PRODUCTS USED FOR DECORATIVE PURPOSES 397 



Bleak {L. alburnus) are employed in the manufacture of arti- 

 ficial pearls. 



Decorative Products of Molluscs (Mollusca). — The 

 shells of the Pearly Nautilus, of many univalves, and numerous 

 bivalves, are largely used for 

 purposes of personal decora- 

 tion by savage races, and 

 to some extent by civilized 

 ones. Some of them are 

 worked up into ornamental 

 knick-knacks even in British 

 watering - places, while the 

 Chinese are singularly skil- 

 ful in the construction of 

 the images of gods, human 

 beings, animals, and plants, 

 from a variety of small 

 shells (fig. 1279). 



Sea- Snails ( Gastropoda"). 

 — The thick shells of some Sea-Snails (species of Cassis, &c.) are 

 made up of layers of different tints, which has rendered them a 

 favourite material upon which to carve cameos (fig. 1280). Pink 

 pearls are the pathological products of certain species, especially 

 the large Conch - Shell iyStrombus 

 gigas) of the West Indies. 



The most famous product of Sea- 

 Snails was, however, the royal dye 



Fig. 1279.— Chinese Shell-ornament 



Fiff. T280— Shell-Cameos 



Fig. 1281. — Murex Eronderi 



known as Tyrian Purple, prepared by the ancient Phoenicians 

 from species of Purpura and Murex (fig. 1281). It is secreted 

 by a gland in the gill-cavity, closely connected with the intestine. 



