ADVERTISEMENT. 



ThivS work (Bulletin l^o. 45) is one of a ?»eries of papers intended to 

 illustrate the collections belonging- to tlie United States, and consti- 

 tuting the jS^ational Museum, of which the Smithsonian Institution was 

 placed in charge by the act of Congress of August 10, 1846. 



The publications of the Natioiuil Museum consist of two series — the 

 Bulletin, of which this is Ko. 45, in continuous series, and the Proceed- 

 ings, of which the sixteenth volume is now in press. A small edition 

 of each paper in the Proceedings is distributed in pamphlet form to 

 specialists in advance of the publication of the bound volume. 



The Bulletin of the National Museum, the i)ublication of which was 

 commenced in 1875, consists of elaborate papers based upon the collec- 

 tions of the iMuseum, reports of expeditions, etc., while the Proceedings 

 facilitate the prompt i)ublication of freshly-acquired facts relating to 

 biology, anthropology, and geology, descriptions of restricted groups 

 of animals and plants, the discussion of particular questions relative 

 to the synonymy of species, and the diaries of minor expeditions. 



Other papers, of more general popular interest, are printed in the 

 Appendix to the Annual Keport. 



Full lists of the publications of the Museum may be found in the cur- 

 rent catalogues of the publications of the Smithsonian Institution. 



Papers intended for publication in the Proceedings and Bulletin of 

 the National Museum are referred to the Committee on Publications, 

 composed as folloAvs: T. H. Bean (chairman), A. Howard Clark, 11. E. 

 Earll, Otis T. Mason, Leouhard Stejueger, Frederick ^Y. True, and 

 Lester F. Ward. 



S. P. L ANGLE Y, 



Secretary of the Smithsonian Institution. 

 Washington, D. C, July 5th, 1893. 



