ADVERTISEMENT. 



The scientific publications of tlie National Museum consist of two 

 series, Proceedings and Bulletins. 



The Proceeding's, the first volume of which was issued in 1878, are 

 intended primarily as a medium for the publication of original papers 

 based on the collections of the National Museum, setting forth newly 

 acquired facts in biolog}", anthropolog}^, and geolog}^ derived there- 

 from, or containing descriptions of new forms and revisions of limited 

 groups. A volume is issued annually or oftener for distribution to 

 libraries and scientific establishments, and in view of the importance 

 of the more prompt dissemination of new facts, a limited edition of 

 each paper is printed in pamphlet form in advance. The dates at 

 which these separate papers are published are recorded in the table of 

 contents of the volume. 



The present volume is the thirty-first of this series. 



The Bulletin, publication of which was begun in 1875, is a series of 

 more elaborate papers, issued separateh, and, like the Proceedings, 

 based chiefl}^ on the collections of the National Museum. 



A quarto form of the Bulletin, known as the ""Special Bulletin," has 

 been adopted in a few instances in which a larger page was deemed 

 indispensable. 



Since 1902 the voUimes of the series known as " Contributions from 

 the National Herbarium," and containing papers relating to the botan- 

 ical collections of the Museum, have been published as Bulletins. 



Richard Rathbdn, 

 Acting Secretary of the Smlthso7iian Institution. 



January 22, 1907. 



