INTRODUCTION. 15 



quelitly lose their delicate spines and foliations, by being 

 suffered to remain beating about on the shore. 



As land and river shells are seldom so beautifully 

 formed, marked, or colored, as those of the ocean, they are 

 in consequence rarely so much prized; however, they 

 form an interesting part in all collections. 



The collector should always keep the following objects 

 in view, whenever he commences the arrangement of his 

 shells : 



First. The order to which they belong, that is, whether 

 they are to be classed with the Multivalves, (i. e. shells of 

 many valevs) ; Bivalves, (shells of two valves) ; or Uni- 

 valves, (shells of one part of piece only) : which three grand 

 divisions constitute the leading distinctions of shells. 



Secondly. He should be careful to place them in the 

 proper genus of the order to which they belong. And, 



Thirdly. He should avoid misplacing or confusing the 

 species which appertain to each genus. And if, in the course 

 of his studies, he should be fortunate enough to obtain any 

 hitherto undiscovered genus, species, or variety, he should 

 make such an accurate description and drawing, as would, 

 by submitting them to the opinion and judgment of the 

 scientific, confirm him in the correctness of his own con- 

 clusions, and tend to promote the general advancement of 

 conchological knowledge. 



THE METHODS OF PRESERVING AND CLEANING SHELLS. 



IF the shell contains the animal alive, it will be neces- 

 sary to immerse it in boiling water for a few minutes; 

 then plunge it into cold water, which will cause the ani- 



