ADVERTISEMENT. 



This work (Bulletin ^o. 45) is one of a scries of papers intended to 

 illustrate the collections belongiuji' to the United tSttites, and consti- 

 tuting the National Museum, of which the Smithsonian Institution was 

 placed in chai'ge by the act of Congress of August 10, 164(1, 



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

 Bulletin, of which this is No. 45, in continuous series, and the Proceed- 

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

 of each pai)er 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 publication of which was 

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

 tions of the Museum, reports of expeditions, et<'., while the Proceedings 

 facilitate the prompt publication of freshly-acquired facts relating to 

 biology, anthropology, and geology, des(!riptions of restricted groups 

 of animals and plants, the discussion of particular questions relative 

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



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

 Appendix to the Annual Eeport. 



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

 rent catalogues of the publications of the tSmithsonian Institution. 



Papers intended for publication in the Proceedings and Bulletin of 

 the National Museum are referred to the Committee on Publications, 

 composed as follows: T. H. Bean (chairman), A. Howard Clark, K. E. 

 Earll, Otis T. Mason, Leonhard Stejneger, Frederick W. True, and 

 Lester F. Ward. 



S. P. Langlev, 

 ISt'crcUiri) of the Smithsonian Institution. 



Washington, 1). C, July 5th, 1893. 



