GASTROPODA. 23 



own shores. The opercula of Turbo petholatus (fig. 11), from the 

 Indian and Pacific Oceans, are frequently mounted in gold and 

 silver as scarf-pins, car- rings, ice 



. li. 



*s 



' / 



Top-shell ( Turbo petholatus). (From the Indo-Pacific Ocean.) 

 a. Inner surface of operculum, b. Exterior of ditto. 



The "Ear-shells " or " Ormers " {Halioticlce) are found adhering [Case 11, 

 to rocks in most parts of the world with the exception of South B-D -3 

 America. They are lined with fear], and many exhibit splendid 

 colours and sculpture externally. Like the Limpets they hold on 

 to the rocks with such tenacity that it is absolutely impossible to 

 remove some of the larger species by force without injuring the 

 shell. Boiling water or mustard and water poured over them will, 

 however, soon compel them to relinquish their hold. The shell of 

 Haliutis is pierced by a series of holes parallel with the left margin. 

 Through such of them as are open the animal protrudes a slender 

 filament or feeler, and the water also finds its way through them 

 to the gills beneath. 



The single British species {H. tuberculata) is not actually found 

 on the English coast, but common on rocks and stones at low- 

 water in the Channel Islands. It is frequently eaten by the poor 

 of those islands and the north of France ; other species in New 

 Zealand, China, Japan, West Africa, and elsewhere, constitute a 

 common article of diet among the natives. Haliotis-sheWs are 

 largely used in the manufacture of pearl ornaments, and in all kinds 

 of inlaid work. 



The "Keyhole Limpets" and "Slit Limpets" {Fissurellida:) j C H e U > 



