ADVKirriSKMENT. 



This work (liullctiu No. 40) is one of a scries of i)iii)ers intended to 

 illustrate the collections belongin<^ to the United States, and consT;i- 

 tuting the National Museum, of which the Smithsonism Institution 

 was placed ia charge by the act of Congress of August 10, 1S40. 



The publications of the Xationai Museum consists of two series — the 

 Bulletin, of which this is No. 40, in continuous scries, and the Proceed- 

 ings, of which the sixteenth volume is now in jners. A small e«litioii 

 of each i)aper in the Proceedings is distributed in pam]»hlct form to 

 specialists iu advance of the i)ublicati<Mi of the bound volume. 



The Bulletin of the National Museum, the publication of whic i was 

 commenced in 1.S75, consists of elaborate papers based upon the col- 

 lections of the Museum, reports of ex'iteditions, etc., while the Proceed- 

 ings facilitate the prompt publication of freshly-acquired facts relating 

 to biology, anthropoh)gy, and geology, descrii)tions of restricted ;;roups 

 of animals and plants, the discussion of particular (juestions relative 

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



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

 Ai>i)endix to the Annual Report. 



Full lists of the ])uldications of the Museum may be found in the 

 current catalogues of the publications of the Smithsonian Institution. 



Papers intended for i)ublication iu the Proceedings and Bulletin of 

 the National Museum are referred to the Committee on Publications, 

 comi)osed as follows: T. H. Bean (chairman), A. Howard Clark, E. E. 

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

 Lester F. Ward. 



S. P. Langley, 

 ISecretary of the Smithsonian Institution. 



Washington, August 31, 1893. 



