PREFACE. 
XV 
of forming new genera, as suggested by 
certain modern conchologists. 
Considerable alterations have likewise 
been made in the descriptions at the head 
of each genus, which, being founded on a 
minute examination and comparison of 
species, it is hoped may render the tech- 
nical definitions more clear and satisfac- 
tory, and less difficult to be impressed 
upon the memory. 
In the list of descriptive terms, the Latin 
word has been prefixed to the English 
translation or derivative; because it may 
occur to ladies, or to others who follow, 
as an amusement, the pursuit of collecting 
and arranging shells, and who may be 
unaquainted with the dead languages, to 
wish for a reference to some Latin author. 
