XXll PREFACE. 



branches ; for it is, surely, more easy to rf- 

 member a well-defined term, though it be 

 new to the ear, than to discover the exact 

 meaning of one which is capable of a diver- 

 sity 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 coloured 



« 



by the student in conchology, from other 

 specimens, either as an embellishment, or 

 as a very beneficial exercise towards acquir- 

 ing a more intimate knowledge of this pe- 

 culiar science. 



A few Drawings have been added, with a 



