ADVERTISEMENT. 
This work is the twenty-second of a series of papers intended to illus- 
trate the collections of natural history and ethnology belonging to the 
United Stated, and constituting the National Museum, of which the 
Smithsonian Institution was placed in charge by the act of Congress of 
August 10, 1846. 
It has been prepared at the request of the Institution, and printed by 
authority of the honorable Secretary of the Interior. 
SPENCER F. BAIRD, 
Secretary of the Smithsonian Institution . 
Smithsonian Institution, 
Washington , April 26, 1882. 
XI 
