ADVERTISEMENT. 



The Author, in the course of an attempt to arrange 

 a small Cabinet of Shells, had occasion to observe, 

 that in Gmelin's edition of the Systema Naturae, the 

 same species frequently appears under two or three 

 different names; and, on the other hand, that in 

 many instances, two or three different species are 

 confounded together under one specific character. 



By a careful examination of the Synonyma, he has 

 endeavoured to correct these errors, and hopes that 

 other Conchologists, who have a more frequent ac- 

 cess to the extensive Cabinets of the Metropolis, 

 will proceed to examine the specific characters, of 

 which he has sometimes been obliged, where their 

 accuracy is very doubtful, to give only a translation 

 from other works. 



Without the use of Sir Joseph Banks's extensive 

 library, no writer on Natural History can hope to 



