XVlll 
PREFACE. 
its branches ; for it is surely more easy 
to remember a well-defined term, though 
it be new to the ear, than to discover the 
exact meaning of one which is capable of a 
diversity of explanations. 
Of the Plates it need only be said, that 
they are all, without any exception, drawn 
from Nature, and as accurately as an unin- 
structed hand could with much care ac- 
complish. They are intended to illustrate 
the forms of every natural subdivision of 
each genus, and will admit of being co- 
loured by the student in conchology, from 
other specimens, either as an embellish- 
ment, or as a very beneficial exercise to- 
wards acquiring a more intimate knowledge 
of this peculiar science. 
A few Drawings have been added, with 
