PREFACE. XV 



dissented from the Linnsean school have, in- 

 deed, satisfactorily pointed out some flaws 

 in the great fabric of the " Systema Natu- 

 rae ;" but in attempting to eradicate the 

 faulty parts, and to supply their place more 

 fitly, they have injured some of the main 

 supports, and have nearly involved the whole 

 edifice in ruin. 



The following pages are devoted to the 

 task of facilitating the study of conchology, 

 on the method of the Swedish naturalist; 

 and they are written under the firm persua- 

 sion, that a material change is dangerous, 

 even in speculative matters, when the prin- 

 ciple has stood the test of general consent, 

 and when the means of reaching perfection 

 are not yet, and, perhaps, may never be, at- 

 tainable. 



