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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; those in quarto constituting the Smithsonian Con- 

 tributions to Knowledge. The quarto series includes memoirs 

 embracing the records of extended original investigations and re- 

 searches, resulting in what are believed to be new truths and con- 

 stituting 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 ; museum 

 catalogues ; reports of explorations ; aids to bibliographical investi- 

 gations, etc., generally prepared at the express request of the Insti- 

 tution, and at its expense. 



In the Contributions to Knowledge, as well as in the Miscel- 

 laneous Collections, the actual date of the publication of each 

 article is that given in the Table of Contents, and not necessarily 

 that 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 bureaus, and especially for the publication of 

 reports of a preliminary nature. 



S. P. LANGLEY, 

 Secretary, Smithsonian Institution. 



