PREFACE. ix 



to think I really must be mad, for in my eagerness to 

 console them I had rashly promised to write one. 



After this statement of the reason which induced 

 me to undertake this work, it is probable that some, at 

 least, of my readers will expect to find that it has 

 been written in what is termed a "popular style," 

 that all Latin words have been carefully excluded 

 from its pages, and that it will, in short, open up a new 

 and easy cut whereby they may speedily and without 

 fatigue arrive at a thorough knowledge of the subject 

 upon which it treats. I am sorry to disappoint them. 

 A " Royal road to learning " is as great a myth as 

 the " Philosopher's stone " ; knowledge, worthy of the 

 name, can only be acquired by gradual and diligent 

 study. It must not, however, for a moment be sup- 

 posed that I would say a single word in disparage- 

 ment of popular works on Natural History ; many of 

 them are charmingly written, and they are all, more 

 or less, calculated to create a taste for it. This I 

 take to be their mission, and when it has been fulfilled 

 the reader will naturally thirst for further and more 

 precise information. To supply this I have ventured 

 to " rush into print," and I trust this little volume may 

 be found of use as a stepping-stone between works in 

 which the subject is treated of in a popular manner, 

 and those, such as ' British Conchology,' by Dr. Gwyn 

 Jeffreys, in which it is more fully and far more ably 

 handled. 



As to Latin names, it is obviously much more 

 difficult to learn many languages than to acquire a 

 knowledge of one. Hence it is that, throughout the 



