ADYERTISEMEKT. 



This work (Bulletin No. 48) is one of a series of papers inteuded to 

 illustrate the collections l)elongiug- to the United States, and constitut- 

 iug- the National Museum, of which the Smithsonian Institution was 

 placed in charge by the act of Congress of August 10, 1840. 



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

 Bulletins, of which this is No. 48, in continuous series, and the Proceed- 

 ings, of which the seventeenth 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 Bulletins of the National Museum, the publication of which was 

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

 tions of the Museum, reports of expeditions, etc., while the Proceed- 

 ings facilitate the prompt publication of freshly-acquired facts relating 

 to biologj^, 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 

 Ap])endix to the Annual Eeport. 



Full lists of the i^ublications 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 Bulletins of 

 the National Museum are referred to the Committee on Publications, 

 composed as follows: F. W, Time (chairman), R. Edward Earll (editor), 

 T. H. Bean, Otis T. Mason, Leonhard Stejneger, and Lester F. Ward. 



S. P. Langley, 



Secretary of the Sniithsonian Institution. 



Washington, D. C, October S, 1894. 

 II 



