PROSPECTUS, 



Giir Plates, but selecting the most characteristic speci- 

 mens in illustration, we shall devote One Plate f very 

 rarely more J to the elucidation of each Genus, and 

 endeavouring as we proceed to ascertain the exact 

 relation naturally existing between the various Genera, 

 we shall give at the conclusion a Classification, arranged 

 according to the more enlightened views we shall then 

 have obtained. 



The Plates of this Work will be all not only original^ 

 but executed in his best manner, by a person of gener-^ 

 ally acknowledged superiority of talent, by one who 

 has already largely contributed by his labours to the 

 advancement of Science in several branches of Natural 

 History, a person whose entire labours for more than 

 thirty years have been devoted to such useful and 

 scientific objects: when we mention the name of 



JAMES SOWERBY, F. L. S. M.G.S.&c. 



we are sure the scientific Public will credit us for 

 our intention to furnish it with correctly executed 

 Engravings. Indeed, our whole Work will be original, 

 though we have no objection to adopting the phrases 

 and language of those who have preceded us ; some- 

 times we shall gather information from them, and as far 

 as we think they have done well we cannot do better than 

 follow them, but never without examination ; when- 

 ever we find them obscure or inadequate we will 

 endeavour to explain and amend. Each of our Plates 

 will be accompanied by a leaf, or more, of Letter- 

 Press; in which we shall give a definition of each 

 Genus and point out those characters in which it 

 differs from others nearest in resemblance to it, and 

 thus establish the relation between the Genera. To 

 render this Work as useful as possible, we shall men- 

 tion the Land, Fresh Water, and Marine Nature of 

 each Genus ; point out the Strata in which the fossil 

 species occur, as far as we are acquainted with them 

 bryr our own observation ; and add such general remarks 

 a.s may appear to us strikingly necessary in illustratiou 



