ADVERTISEMENT 



The scientific publications of the National Museum include two 

 series, known, respectively, as Proceedings and Bulletin. 



The Proceedings series, 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 organi- 

 zations and to specialists and others interested in the different 

 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 eighty-first of this series. 



The series of Bulletins, the first of which was issued in 1875, contains 

 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 and 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 bj^ 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, February S, 1933. 

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