ADVERTISEMENT. 



This work (Bulletin No. 23) is the twenty-ninth of a series of papers 

 intended to illustrate the collections of natural history and ethnology 

 belonging to the United States, and constituting the l^ational Museum, 

 of which the Smithsonian Institution was placed in charge by the act of 

 Congress of August 10, 1846. 



It has been j^repared at the request of the Institution, and printed 

 by authority of the honorable Secretary of the Interior. 

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

 Bulletins, of which this is No. 23, in continuous series, and the Proceed- 

 ings, of which the eighth volume is now in press. 



The volumes of Proceedings are i^rinted, signature by signature, each 

 issue having its own date, and a small edition of each signature is dis- 

 tributed to libraries promj)tly after its publication. 



From time to time the publications of the Museum which have been 

 issued separately are combined together and issued as volumes of the 

 Miscellaneous Collections. These are struck off from the stereotype 

 plates from which the first edition was printed, and in this form are 

 distributed by the Smithsonian Institution to libraries and scientific 

 societies throughout the world. Volume 13 of these collections includes 

 Bulletins 1 to 10 inclusive; volume 19, volumes 1 and 2 of the Proceed- 

 ings; volume 22, volumes 3 and 4 of the Procedings; and volume 23, 

 Bulletins 11 to 15 inclusive. 



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

 rent catalogues of the publications of the Smithsonian Institution. 



SPENCER F. BAIED, 

 Secretary of the Smithsonian Institution. 



Smithsonian institution, 



Washington, September 20, 1885. 



