limited means, it is published at the cost of paper and 

 printing. 



The three volumes of plates now published com- 

 plete the series of Gasteropodous and Pteropodous Mol- 

 lusca. They form, I believe, the largest number of 

 figures of the species of these animals that has hitherto 

 been brought together in one work. 



The explanations of the plates have been formed into 

 a separate volume, for the purpose of more easy con- 

 sultation ; and to carry out this view, the references to 

 the plates forming the first volume of the series have been 

 reprinted. To this part of the work has been added a 

 systematic distribution of the species figured, with the 

 characters of the orders, families, and their subdivisions, 

 and a list of the genera of Mollusca and their syno- 

 nyma, originally printed in the Proceedings of the Zoolo- 

 gical Society for 1847. 



The series of plates containing the Conchiferous 

 Mollusca is in hand, and will be published at a future 

 period. 



JOHN EDWARD GRAY. 



British Museum, 



February 12, 1850. 



