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, anthi'opology, and geology, with descriptions of new 

 forms and revisions of Umited groups. Copies of each paper, in 

 pamphlet form, are distributed as published to libraries and scien- 

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

 tains 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 speci- 

 mens, 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 head- 

 ing 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. 175 of the Bulletin series. 



Alexander Wetmore, 

 Assistant Secretary, Smithsonian Institution. 



Washington, D. C, April 23, 1940. 



