Vll 



person shall have the preference who shall ultimately 

 offer the liigher advanced price. 



In conclusion, we have first to acknowledge our 

 obligation to W. Swainson, Esq. for his descrip- 

 tions of four new species of the Genus IMitra; in 

 the knowledge of which, having made it his particu- 

 lar study, every Conchologist will readily acknow- 

 ledge his pre-eminence : secondly, to state that this 

 Catalogue has been written under such numerous 

 disadvantages, that we have reason to fear some 

 important errors may have crept in, for which we 

 trust every allowance will be made by the candid 

 scientific reader. 



156, Regent Street, 



