viii PREFACE. 



party, bolder than the rest, ventured to ask, " What 

 are you doing there ? " " I am looking for shells." 

 " Shells ! " he exclaimed, at the same time casting a 

 glance full of meaning towards his companions. 

 " Shells ! If you want shells you should look for them 

 on the sea-shore ; there are none here. You had better 

 come out of that ditch and go home." 



My reply was a silent one, but it was convincing. 

 I picked up a stone and handed it to him ; on the 

 side which had lain next the damp ground there 

 were two or three specimens of Zonites nitidus. 

 The men stared first at the shells and then at me, in 

 evident astonishment ; and from the remarks they 

 made to one another it was clear that, even if they 

 still believed me to be insane, the thought was be- 

 ginning to dawn upon their minds that there might 

 perhaps, after all, be " some method " in my madness. 

 To be brief, I most gladly complied with their request 

 that they might be permitted to accompany me in my 

 ramble. On parting from them in the evening, they 

 one and all declared they had spent " a happy day," 

 and expressed their determination to employ, for the 

 future, some of their leisure hours in studying the 

 habits of the creatures the outlines of whose history I 

 had, during our walk, endeavoured to trace. 



Great, however, was their disappointment when, in 

 answer to their inquiries, I confessed my inability to 

 recommend them a book containing descriptions and 

 illustrations of all the species at present known, which 

 could be purchased at a price suited to their means ; 

 and after I had left them I began, for the first time, 



