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Limpet. — These molluscs are plentiful on almost every shore 
where there are rocks which are regularly covered and left by the 
tide. If given a sudden sharp tap they are easily dislodged, but 
when they have warning of danger their shells may be smashed to 
pieces before they will release their hold. When left by the receding 
tide they often crawl slowly over the seaweed and rocks in search of 
food. _Our second illustration of limpets shows one moving on the 
glass side of an aquarium. In this position it will be seen to have 
a mouth and two horns somewhat like those of an ordinary 
terrestrial snail. 
Periwinkle.— One of the commonest molluscs of our coasts is the 
ordinary periwinkle. It occurs as several varieties, some a dull 
bluish colour, others reddish brown, while still another form is 
banded with brown and yellow. It feeds on all kinds of healthy 
and decaying seaweed. 
Dog Winkle. — While searching among the seaweed at low tide 
a large number of small whelk like shells are sure to be discovered, 
some quite dormant, others being dragged over the rocks by their 
hungry owners in search of food. Many of these will be a dazzling 
white, others a yellowish hue, while a third group will be of quite a 
sombre brownish tint. However, all these belong to the same 
species, in spite of the great diversity of colour displayed, and are 
the common dog winkle. 
Pearly Tops. — These shells owe their common name to the 
likeness they bear to a pyramid, or an inverted top. They are 
easily distinguished by their shape and the similarity of the mouth 
of the shell to mother of pearl. 
Oyster.— This mollusc is so well known as an article of diet that 
a description here would be superfluous. Those required for market 
are dredged up when quite young from the natural beds which lie at 
some depth below the surface. From there they are transferred to 
artificially prepared shallow banks, where they are allowed to grow 
until again dredged up for “ Whitstable Natives.” 
Razor-fish.— On many a gravelly beach, when the tide is low, a 
number of yellowish-pink elongated shells may be seen lying 
embedded in the sand. The popular name has been derived front 
their fanciful resemblance to the handle of a razor. Sometimes 
there are literally thousands of these shells, some in a more or less 
good state of preservation ; but as they are extremely fragile, the 
majority are hopelessly broken. Though so many shells are about, 
not one of them will be found tenanted. The animals which dwell 
in them are exclusively subterranean, living in vertical burrows in 
the sand. When the tide covers them they are very near the surface, 
but when the sands are high and dry they retreat to the further 
extremity of their hole. Their homes are usually marked by little 
punctures in the sand. Through these they frequently squirt tiny 
jets of water in their hurried retreat from the surface if it be shaken 
by the approach of a possible enemy. Razor-fish make splendid 
bait, and are often used for human food. 
Acorn Barnacles. — Every visitor to the sea-side who has made 
any excursions among the rocks is sure to have noticed the myriads 
of tiny whitish shells which so often cover them. They fix themselves 
to rocks, the shells of molluscs and crabs, and even sea-weed, and in 
such numbers that they often completely cover their host. If one 
of these be carefully observed, it will be noticed that there is a sort 
of roof divided down the middle. While left dry the shell is kept 
