ADVERTISEMENT. 
The scientific publications of the National Museum consist of two 
series—Proceedings and Bulletins. 
The Proceedings, 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 biology, anthropology, and geology derived there- 
from, or containing descriptions of new forms and revisions of lim- 
ited groups. A volume is issued annually or oftener for distribution 
to libraries and scientific establishments, and, in view of the impor- 
tance 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 sixty-second of this series. 
The Bulletin, publication of which was begun in 1875, is a series 
of more elaborate papers, issued separately, and, like the Proceedings, 
based chiefly 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 volumes of the series known as “Contributions from 
the National Herbarium,” and containing papers relating to the 
botanical collections of the Museum, have been published as Bulletins. 
Wiii1amM DEC. RAvENEL, 
Administrative Assistant to the Secretary, 
in Charge of the United States National Museum. 
NoveMBER 26, 1823. II 
