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 organizations and to specialists and 

 others interested in the ditTerent subjects. The dates at which these sepa- 

 rate 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 volumes), 

 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 botani- 

 cal collections of the Museum. 



The present work forms No. 190 of the Bidletin series. 



Alexander Wetmore, 

 Secretary, Smithsonian Institution. 

 II 



