116 
It may possibly be remarked, that in the preced* 
ing description of the genera of shells, no mention 
has been made by name, of the systems and opi- 
nions of either former or contemporary writers on 
the subject. This omission has not arisen from 
any want of respect to the literary labours of those 
who, with great research and skill, have brought 
the science of Conchology to its present state, or 
of those who, like the author, have availed them- 
selves largely of the written documents furnished 
by works in the German, French, and Latin 
anguages, which have not been translated into our 
own. The names of Testaceological writers, and 
the titles of their books, with short notices on some, 
will be given in another place : but it has appeared 
to be one great source of the uncertainty and con- 
fusion attending this branch of study, that the 
beginner had not only to learn a system, but to 
select one from many extremely different, placed 
for comparison in the same page. It would be 
inconsistent with the professed object of this ele- 
mentary treatise to insert a variety of theoretical 
matter, which could only tend to divert the mind 
