XIV PREFACE. 



logy. That some difficulties do exist in this 

 branch of study, will readily be allowed ; but 

 at the same time we cannot but regret, that 

 the very acknowledgement of their exist- 

 ence has extremely increased their number ; 

 for a supposition seems to have been univer- 

 sally indulged, that conchology lay open as 

 a common field for speculation, in which 

 every individual, whether qualified or not, 

 was at liberty to range, and exercise, with- 

 out restraint, his genius for invention. The 

 consequence has been, that scarcely two 

 writers on the subject have agreed in their 

 opinions, and that this general want of con- 

 currence has aggravated the evils which each 

 endeavoured to remove. 



It is easier to refute error than to establish 

 truth : thus, the several wTiters who have 



