ADVERTISEMENT 



The present seriei*, entitled " Smithsonian IVIiscellaneous Collections," is 

 intended to embrace all the publications issued directly by the Smithsonian 

 Institution in octavo form ; those in quarto constituting the " Smithsonian 

 Contributions to KnoAvledge." The (piarto series includes memoirs, embrac- 

 ing the records of extended original investigations and researches, resulting 

 in what are believed to be new truths, and constituting positive additions to 

 the sum of human knowledge. The octavo series is designed to contain 

 reports on the jii'esent state of our knowledge of particular branches of 

 science; instructions for collecting and digesting facts and materials for 

 research ; lists and synopses of species of the organic and inorganic world ; 

 museum catalogues ; rejDorts of explorations ; aids to bibliographical investi- 

 gations, etc., generally prepared at the express request of the Institution, 

 and at its expense. 



The assignment of a work to one or the other of the tw'o series will some- 

 times depend upon wdiether the required illustrations can be presented more 

 conveniently in the quarto or the octavo form. 



In the Smithsonian Contributions to Knowledge, as well as in the present 

 series, each article is separately paged and indexed, and the actual date of 

 its publication is that given on its special title j^age, and not that of the 

 volume in which it is placed. In many cases works have been published, 

 and largely distributed, years before their combination into volumes. 



While due care is taken on the part of the Smithsonian Institution to 

 insure a proper standard of excellence in its publications, it will be readily 

 understood that it cannot hold itself responsible for the facts and conclusions 

 of the authors, as it is impossible in most cases to verify their statements. 



S. F. BAIRD, 



Secretary S. I. 



