INTRODUCTION. 7 



branch of natural history would be materially faci- 

 litated, and a more natural classification of the various 

 species accomplished, by observing attentively the in- 

 dications Nature herself so often furnishes, which are 

 too frequently overlooked and neglected as unimport- 

 ant, from their being but slightly defined. 



The multiplication of genera which La Marck's 

 classification has occasioned, appears to many unneces- 

 sary, and difficult to comprehend or remember ; it in 

 fact, however, greatly facilitates and simplifies the stu- 

 dy of Conchology, by confining within a narrower 

 compass the too widely extended genera of Linnaeus, 

 and remodelling those that have been blended toge- 

 ther in strange confusion, either with regard to the 

 figure or the habitat of the shell, or the structure and 

 functions of the animal ; each of which now being dis- 

 tinguished by certain more or less strongly defined ge- 

 neric characters, peculiar to itself, may at once be re- 

 cognised from its congeners, and, by a moderate exer- 

 cise of memory, placed in its proper and most natural 

 class. 



It is not, however, the writer's intention to enter in- 



