lv 
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- 
sical 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. 
Britisn Museum, 
February 12, 1850. 
