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 collec- 

 tions 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 organ- 

 izations and to specialists and others interested in the different sub- 

 jects. The dates at which these separate papers are published are 

 recorded in the table of contents of each of the volumes. 



The series of Bulletins., the first of which was issued in 1875, con- 

 tains separate publications comprising monographs of large zoologi- 

 cal 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 

 HerhaHum., in octavo form, published by the National Museum since 

 1902, which contain papers relating to the botanical collections of the 

 Museum. 



The present work forms No. 157 of the Bulletin series. 



Alexander Wetmore, 

 Assistant Secretary., Smithsonian Institution. 



Washington, D. C, Octoler 31, 1931. 

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