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



After having made my obfervations, 

 continues Mr. Adanfon, on great quan- 

 tities of this fpecies, I find tliat all thefe 

 varieties proceed not only from their dif- 

 ferent ages, but alio from the difference 

 of places they are found in : however, in 

 all the Shells, whether young or old, I 

 found a conftant or fixed character in the 

 eye, or beak, which is always pretty ob- 

 tufe, and lituate at about two thirds of the 

 length of the Shell. 



I fhall obferve, in anfwer to the above, 

 that the different ages of Shells certainly 

 make them wear different appearances, in 

 colour, (hape, work, Gfc. ; and I am con- 

 vinced, that fome are even fo greatlv 

 changed from one age to another, that 

 they appear abfolutely different fpecies. 

 The want of opportunities to trace the dif- 

 ferent prcgreffions, grow^th, or changes 

 thefe animals of the deep undergo, is a de- 

 fJeratum which human powers can never 

 attain ; and confequently, we muft always 



be 



