68 C O N C H O L O G Y. 



other inftruftlons^ but only to be judi* 

 cious in his choice. 



The River Shells in general are obferv- 

 ed not to be of a plealing colour, or to 

 have any great variety of colour ; there- 

 fore, in that point, they are lefs curious 

 * than the Land or Sea Shells, 



River Shells are moft generally alfo et- 

 tremely thin, fome have even imagined it 

 a character to diftinguifh them ; but they 

 are miftaken, for though in general River 

 Shells are thin, yet we find Sea Shells as 

 thin ; witnefs the Cymbia, or Paper Nau- 

 tili, fome Pin Die, and many other Sea 

 Shells, as alfo many Land Shells. 



The above is fufficient for colle£llng 

 Shells. Now, to preferve them. As Shells 

 are of a calcareous nature, all acids fliould 

 be avoided as much as poffible ; aft'd even 

 when you kill the fifli, as continued boil- 

 ing them may detriment the Shells, I 



would 



