ADVERTISEMENT 



The present series, entitled Smithsonian Miscellaneous Col- 

 lections, is intended to include all the publications issued directly 

 by the Smithsonian Institution in octavo form, excepting the An- 

 nual Report to Congress ; those in quarto constituting the Smith- 

 sonian Contributions to Knowledge. The quarto series includes 

 memoirs embracing 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 present 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 ; reports of 

 explorations ; aids to bibliographical investigations, etc., generally 

 prepared at the express request of the Institution, and at its expense. 



In the Smithsonian Contributions to Knowledge, as well as 

 in the Smithsonian Miscellaneous Collections, the actual date 

 of the publication of each article is that given on its special title- 

 page or in the Table of Contents of the volume, and not necessarily 

 that of the title of the volume in which it appears. 



The Quarterly Issue of the Smithsonian Miscellaneous Col- 

 lections is designed chiefly to afford a medium for the early pub- 

 lication of the results of researches conducted by the Smithsonian 

 Institution and its branches, and especially for the publication of 

 reports of a preliminary nature. 



Charles D. Walcott, 

 Secretary of the Smithsonian Institution. 



