NOTICE. 



The second part of this Manual is now in preparation, and 

 will be published early in the summer. It will contain an ac- 

 count of the remaining orders of shell-fish: a chapter on the 

 Geographical Distribution of the Mollusca, with a Map of the 

 Marine and Terrestrial Provinces ; a chapter on the distribution 

 of Fossil Shells ; another on the methods of collecting and pre- 

 serving Land, Tresh-water, and Sea-shells ; the Preface ; and an 

 Index of the genera and technical terms . 



The writer desii'es to acknowledge his obligations to Mr. 

 Hugh Gumming, Professor Edward Porbes, and other gentlemen 

 who have assisted him by advice, and the loan of specimens ; 

 also to Mr. Van Voorst, for permission to copy some interesting 

 figures from the " British Mollusca ;" and his thanks are most 

 especially due to Mr. John Edward Gray, Keeper of the Zoolo- 

 gical Department of the British Museum, for access to his library 

 and cabinet, and the use of some of the best engravings which 

 illustrate these pages. 



