A D V E K T I S E M ENT. 
This work is tlie sixteeuth of ii series of papers intended to illnstrate 
the collections of natural history and ethnology belonging to the 
TTnited States, and constituting the National Musenin, of which the 
Smithsonian Institution was jdaced in charge by the act of Congress of 
Angnst 10, 1840. 
It has been prepared at the recpiest of the Institution, and printed by 
authority of the honorable Secretary of the Interior. 
SPENCER F. BAIRD, 
/Secretary of the Smithsonian Institution. 
SmTHSoNiAN Institution, 
Washington, May 20, 1882. 
ii 
