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 collection 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 organi- 

 zations and to specialists and others interested in the different sub- 

 jects. The dates at which these separate papers arc published ape 

 recorded in the table of contents of each of the volumes. 



The present volume is the sixty-eighth of this series. 



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 sj^stematic treatises (occasion- 

 ally 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 (juarto size has been adopted in a few instances in which large 

 plates were regarded as indispensable. In the Bulletin series ap- 

 pear volumes under tlie heading Contributions frovi the United, 

 States National Herhariu/m, in octavo form, published by the Na- 

 tional Museum since 1902, which contain papers relating to the 

 botanical collections of the Museum. 



Alexander Wetmoke, 

 Ass/stant Secretary, Sinithstoy^'/on Inst If ut Jon. 



Washington, D. C. January 13, 1927. 



