Page:Walcott Cambrian Geology and Paleontology I.djvu/7



The present series, entitled "Smithsonian Miscellaneous Collections," is intended to embrace the principal publications issued directly by the Smithsonian Institution in octavo form; those in quarto constituting the "Smithsonian 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 present series, each article bears a distinct number, and is also separately paged unless the entire volume relates to one subject. The actual date of the publication of each article is that given on its special title-page, and not that of the volume in which it is placed. In many cases papers have been published and largely distributed, several months before their combination into volumes.

(iii)