PREFACE. 



Although our work is long, our Preface need not be so ; 

 nor, indeed, need it be more than a grateful record of the 

 obligations we are under to the many friends who have 

 assisted in our task. That a History of the British Mol- 

 lusca in accordance with the present state of Natural His- 

 tory Science, and of the present knowledge of our native 

 species was required, will, we are confident, be denied 

 by no person qualified to offer an opinion upon the matter. 

 Materials for such a work have long been in course of 

 collection, and amply amassed by ourselves and others. 

 We entered upon the task diffidently, and not before the 

 field was fairly open, those best qualified for the labour 

 urging us to attempt what had almost become a duty. 

 The invaluable and classical collection of British shells in 

 the possession of Mr. Gwyn Jeffreys, and the extensive 

 experience of its liberal proprietor, placed within the reach 

 of that energetic investigator, materials for a work like 

 this, such as no other naturalist could command, but the 

 imperious demands of professional avocations withheld the 

 leisure where there was both will and ample knowledge. 

 Mr. Alder, too, profoundly versed in British Malacology, 

 and gifted with the power of delineating, at once accu- 

 rately and artistically, the animals whose external clothing 

 and internal structure had alike engaged his attention, 

 was already occupied with a section of the subject that 



