PREFACE. 
It may be necessary in introducing this little volume, to 
state, that it is strictly conchological, and that it is com- 
piled for the use not only of those who wish to acquire 
an elementary acquaintance with the subject, but also of 
authors and others, who, desirous of extending their know- 
ledge and pursuing their researches, require a book of re- 
ference, containing a general outline of what has been done 
by those who have trodden the same path before them. It 
has been thought advisable, for general convenience, to ar- 
range the principal part of the information in alphabetical 
order ; adding tables of the systems of Lamarck and De 
Blainville, to facilitate the systematic pursuit of the science. 
Persons of the class first alluded to, will find great assist_ 
ance in the explanation of technical words, their application 
being further illustrated, in most cases, by a reference to the 
figures ; and, although they might have been multiplied, it 
is trusted that enough are given for every useful purpose. 
The definition of the Classes, Orders, Families, and Ge- 
nera, in the system of De Blainville, and a tabular view, 
are presented for the use of those who prefer it, or who 
wish to compare it with that of Lamarck. 
In the explanation of the figures, will be found a syste- » 
matic arrangement of shells, according to Lamarck, includ- 
ing the names of genera established or proposed since the 
publication of his system. The descriptions of established 
