ADVERTISEMENT 



The scientific publications of the National Museum include two 

 series, known, respectively, as Proceedings and Bulletin. 



The Proceedings, begun in 1878, is intended primarily as a medium 

 for the publication of original papers, based on the collections of the 

 National Museum, that set forth newly acquired facts in biology, 

 anthropology, and geology, with descriptions of new forms and 

 revisions of limited groups. Copies of each paper, in pamphlet 

 form, are distributed as published to libraries and scientific organiza- 

 tions and to specialists and others interested in the diflFerent subjects. 



The dates at which these separate papers are published are recorded 

 in the table of contents of each of the volumes. 



The present volume is the seventy-third of this series. 



The Bulletin, the first of which was issued in 1875, consists of a 

 series of separate publications comprising monographs of large 

 zoological groups and other general systematic treatises (occasionally 

 in several volumes), faunal works, reports of expeditions, catalogues 

 of type-specimens, special collections, and other material of similar 

 nature. The majority of the volumes are octavo in size, but a 

 quarto size has been adopted in a few instances in which large plates 

 were regarded as indispensable. In the Bulletin series appear 

 volumes under the heading Contributions from the United States 

 National Herbarium, in octavo form, published by the National 

 Museum since 1902, which contain papers relating to the botanical 

 collections of the Museum. 



Alexander Wetmore, 

 Assistant Secretary, Smithsonian Institution. 



Washington, D. C, July 3, 1929. 

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