12 
SHELL GALLERY. 
9-11. 
Cases 
12-18. 
been described. The specimens of P. adansoniana and P. leyrichi 
exhibited in case 9, are among the finest acquisitions to the shell 
collection of recent years. 
The " Ear-shells " or " Ormers " (Haliotidm) are found adhering 
to rocks in most parts of the world, with the exception of South 
America. They are lined with pearl, 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 
Haliotis 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. tubercidata) 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, HaHoiis-sheWs are largely used in 
the manufacture of pearl ornaments, and in all kinds of inlaid work. 
The Trochidce and TurUnida are two extensive families, the 
animals of which are very much alike, and mainly distinguished by 
Fig. 6. 
Top-shell (Turbo petholatus). (From the Indo-Pacific Ocean.) 
a. Inner surface of operculum, b. Exterior of ditto. 
the operculum, which in the former is horny, and shelly in the 
latter. The shells of these families are beautifully pearly within, 
