ADVERTISEMENT 



The scientific i3ublications of the National Museum include two 

 series, known, respectively, as Proceedings and Bulletm. 



The Proceedings^ begun in 1878, are intended primarily as a medium 

 for the publication of original papers, based on the collections of the 

 National Musemn, that set forth newly acquired facts in biology, 

 anthropology, and geology, with descriptions of new forms and re- 

 visions 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 different subjects. 



The dates at which these separate papers are published are recorded 

 in the table of contents of each of the volumes. 



The present volume is the ninety-first of this series. 



The Bulletin, the first of which was issued in 1875, consists of a 

 series of separate publications comprising monographs of large zoo- 

 logical 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 na- 

 ture. 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 un- 

 der the heading C ontnhutions from the United States National Her- 

 barium, in octavo form, published by the National Museum since 

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

 Museum. 



Alexander Wetmore, 

 Assistant /Secretary, Smithsonian Institution. 



m 



535587—48 



