4 PREFACE 



The kind reception given to my "West Coast Shells," 

 and my other efforts to popularize the study of mol- 

 lusks, led to the publication, late in 1904, of a larger 

 volume, entitled "West American Shells." The great 

 conflagration in San Francisco, following the earthquake 

 of April, 1906, destroyed practically all of the unsold 

 copies of that last edition, though most of the cuts had 

 been previously removed to a place of safety. The un- 

 settled conditions and the increased duties following the 

 earthquake prevented my rewriting the book until 

 last summer. It is now to be published under the old 

 name, as that seems more appropriate. 



While it cannot be hoped that it is free from mistakes, 

 it is certain that some of the errors of the last edition 

 have been corrected, and an honest attempt has been 

 made to provide a handbook both readable and reliable. 



It is not so complete and full as some teachers desire, 

 and no one feels more deeply than the author our need 

 of a manual, in which the shells of this region shall be 

 fully described in scientific language. We have assur- 

 ances that such a volume or series of volumes will be 

 published at Washington in due time, and that much 

 material has already been collected for that purpose. 

 The work is a great one, however, and years may elapse 

 before the volumes are issued. Therefore it has not been 

 thought wise to delay the publication of this handbook, 

 which was never designed to take the ]:>lace of an 

 official manual. 



Though much difficulty has sometimes been experi- 

 enced in deciding between the claims of rival syno- 

 nyms, the name usually selected has been the latest one 

 adopted by standard authors, particularly those con- 

 nected with the National Museum. In case of real 

 doubt a conservative course has been followed. 



