

PREFACE. 



A BOOK containing a sufficient number of figures to assist con- 

 chologists in the determination of the shells they may occasionally 

 acquire, has long been a desideratum. 



We have, it is true, the extensive work of Martini and Chem- 

 nitz, the more confined publications of Knorr, of Gaultieri, of 

 Rugenfuss, Lister, Rumphius, Petiver, and others ; but in no 

 instance, except the first-mentioned, has any attempt been made 

 to include a figure of every species. The great expense attending 

 such pubUcations, and the want of sufficient encouragement in 

 purchasers, has hitherto operated to prevent the accomplish- 

 ment of so desirable an undertaking. It has therefore been the 

 endeavour of the Author, in the absence of larger and more costly 

 publications, to supply their place by a work which will incorpo- 

 rate in one volume figures of all the known shells, reduced indeed 

 ■to a small size, but with a degree of accuracy that it is hoped, will 

 not only enable the conchologist to fix upon any particular species 

 he may wish to define, but also to arrange his collection by inspec- 

 tion, without the trouble of consulting other publications on the 

 subject. 



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