ADVERTISEMENT. 



The publications of the National :\Iuseani consist of two series: 

 Proceeding-s and Bulletins. 



The Proceedings, the tirst volume of which was issued in 1878, are 



intended primarily as a medium of publication for newly-acquired 



facts in biology, anthropology, and g-eolog-y, descriptions of new forms 



of animals and plants acquired by the National Museum, discussions of 



nomenclature, etc. A volume is issued annually or oftener for distri- 



' -tion to libraries, while in view of the importance to science of the 



mpt publication of descriptions of new species, a limited edition of 



1 paper is printed in pamphlet form in advance. 



.lie present volume is the twenty-hfth of the series. 



The Bulletin, publication of which was begun in 1875, is a series 



of more elaborate papers, issued separately and based for the most 



part upon collections in the National Museum. They are mono- 



g-raphic in scope, and are devoted principally to the discus^sion of large 



zoological groups, bibliographies of eminent naturalists, reports of 



expeditions, etc. 



A quarto form of the Bulletin, known as the ''Special Bulletin,'' has 

 been adopted in a few instances in which a larger page was deemed 

 indispensable. 



The Annual Report of the National Museum (being the second vol- 

 ume of the Smithsonian Report) contains papers chiefly of an ethno- 

 logical character, describing collections in the National Museum. 



Papers intended for publication by the National Museum are usually 

 referred to an advisory committee, composed as follows: Frederick 

 W. True (chairman), William H. Holmes. George P. Merrill, James 

 E. Benedict, Otis T. Mason. Leonhard Stejneger, Lester F. Ward, and 

 Marcus Benjamin (editor). 



S. P. Langley, 

 Seeretarij of the Smithsonian Institution. 



