242 



THE SEA SHORE 



recurved apex, and is surrounded by a rim internally ; while in the 

 Notched Limpets (genus Emarginula) it is represented by a fissure 

 on the anterior margin of the cone. In all, however, the hole 

 or notch serves the same purpose, for it 

 is the means by which water enters the 

 siphon. 



It is doubtful whether we ought to 

 claim the beautiful Ear shell (Haliotis 

 tiiberculata) as one of our own, but it is 

 generally included among the British mol- 

 luscs on the ground that it is abundant 

 on the coast of the Channel Islands, where 

 it is called the Omar ; and it ie certainly 

 too beautiful an object to be excluded from 

 the British species without ample cause. 



It belongs to the family HaUotidce, 

 and our illustration will show that the 

 shell is less elevated than that of limpets, 

 and that the spire, though not prominent, 



is a fairly well-formed spiral. All along the outer lip of the very 

 large aperture is a series of perforations, occupying the summit 

 of a prominent, spiral ridge, and becoming gradually smaller and 

 smaller towards the spire. The whole shell is pearly in structure, 

 and displays a great variety of rich colouring. It is used largely 

 for inlaying and other ornamental purposes, and for making the 

 so-called pearl buttons. The animal is used largely as an article 

 of food in the Channel Islands, but it is of so tough a nature that 

 it requires a vigorous beating previously to being cooked. 



Fio. 169. Haliotis 



FIG. 170. lanthina fragilis 



The same family contains the beautiful violet lanthina, which 

 also is not a British species, but a free-swimming oceanic snaiL It 

 is, however, occasionally drifted to our shores, though generally in 



