INTRODUCTION. 
This catalogue and index are supplemental to those published in 
1901 as Bulletin No. 177. These begin where those end; but there 
will be found in this index some entries — additional and corrective — 
which refer to papers covered by Bulletin No. 177. The two bulletins 
constitute a general catalogue and index of the publications of the 
Geological Survey from its organization, in 1879, to the present time. 
It is hoped that within the next few years someone will have the time 
and the inclination to combine the two and bring the work down 
to date. 
The indexing has been done in a desultory manner, as opportunity 
arose; and in the work the writer has had the assistance of other 
members of the editorial corps, viz, Messrs. Charles A. Mansuy, Lau- 
rence F. Schmeckebier, and George M. Wood. 
P. C. W. 
