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, 

 antlaropology, and geology, with descriptions of new forms and revis- 

 ions of limited groups. Copies of each paper, in pamphlet form, are 

 distributed as published to libraries and scientifiic organizations 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 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. 



The present work forms No, 135 of the Bulletin series. 



Alexander Wetmore, 

 Assistant Secretary, Smithsonian Instituition. 



Washington, D. C, December 16, 1926. 



in 



