PREFACE. V 



class e." This is a sufficient acknowledgement that nothing 

 more is to be expected on the subject, and that the omitted 

 genera are not considered by him as essential to the series. 



A regular reference has been made to Gmelin as far as 

 relates to the distinct species; and the Catalogue will serve 

 also as an Index to Lister, Gualtieri, and Martini and 

 Chemnitz, the letter C. denoting the united labours of the 

 latter authors. 



The figures of Donovan and Montagu, with the de- 

 scriptions also of the latter, have been constantly quoted 

 for the British Shells. It must be observed, that where 

 the species is confined to Britain, the word alone is men- 

 tioned. If it occurs also in other parts of the world, it is 

 denoted by " Britain, &c." Thus all the shells that have 

 hitherto been observed on our coasts will be immediately 

 detected. 



