PREFACE. 
Vii 
rjtv.arked upon a shell] the record of which is still 
commemorated in the derivation of our terms, tes¬ 
tament, and attestation. As one of the principal 
agents of decomposition and gradual dissolution, 
the geologist will find his researches assisted by an 
examination into their rapid and astonishing powers 
of perforating and disuniting rocks of calcareous 
.sandstone, limestone, marble, and even the hardest 
masses of granite and porphyry, wherever they 
come in contact with the ocean : and by a compa¬ 
rative examination of the different stratifications of 
marine testaceous depositions, he may eventually 
be led to some important conclusions as to the 
probable elevation of the general deluge. 
But the systematical conchologist has a loftier 
and more noble object in his pursuit ] to unfold a 
leaf from the great book of Nature : that portion 
of which, respecting the treasures of our own 
islands, it has been our study to contemplate, and 
our wish to explain. Although we have not been 
honored by the use of tne library of the venerable 
patriarch of natural history, Sir Joseph Banks, 
without which, we are informed by a modern com¬ 
piler on this subject*, “ no writer can hope to at¬ 
tain any tolerable degree of perfection 3” we have 
not been entirely without the means by which this 
study can be best understood and most faithfully 
displayed. The whole of what is described, our¬ 
selves have seen and accurately examined, with the 
exception of such as are indistinct and not to be 
found in cabinets, a few of the rarer and nearly 
unique species, and some microscopic objects, the 
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b 2 
number 
