ADVERTISEMENT 
The Smithsonian Miscellaneous Collections series contains, since the 
suspension in 1916 of the Smithsonian Contributions to Knowledge, 
all the publications issued directly by the Institution except the An- 
nual Report and occasional publications of a special nature. As the 
name of the series implies, its scope is not limited, and the volumes 
thus far issued relate to nearly every branch of science. Papers in 
the fields of biology, geology, anthropology, and astrophysics have 
predominated. 
LEONARD CARMICHAEL, 
Secretary, Smithsonian Institution. 
(iii) 
