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 ANn- 
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. 
ll 
