G.\STEROPODA. 



281 



The Cowrie shells are employed by Asiatic island- 

 ers to adorn their dress, to weight their fishing-nets, 

 and for barter. Specimens of them were found by Br. 

 Layard in the ruins of Nimroud. The Money cowrie 

 {Cyjprma ?noneta) is used as money by the Africans : 

 hundreds of tons are imported to Liverpool and ex- 

 ported for barter.* 



The Harp-shells {Harpa) are recognisable by the 

 prominent ribs upon then- surface, the last of which 

 forms the marginal border. These shells are very 

 beautiful ; the animal (Fig. 217.) is furnished with a 

 large foot, broad in front, and pointed i3osteriorly ; its 

 tentacles are provided with eyes situated near their 

 bases ; it has no operculum. 



The Helmet-sheUs (Cassis) are of an oval shape, 



Fig. 220.— cassis tubk!;osa. 



* From a coarse comparison of the CowTie shells to a pi^'s back, 

 tJiey were vulgarly known to the Portuguese as Porcellane (Porcellus, 

 a little pig;. When the beautiful ware known as china was first im- 

 ported, the resemblance of its glaze to the enamel of the Cowrie 

 shell caused it to be called '^ Porcelain." 



