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 organiza- 

 tions and to specialists and others interested m 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 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 vol- 

 umes), faunal works, reports of expeditions, catalogs 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. 194 of the Bulletin series. 



Alexander Wetmore, 



Secretary, Smithsonian Institution. 

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