108 THE U. S. GEOLOGICAL SURVEY 



Geologic Atlas Folios. Under this title data regarding geologic 

 conditions is presented. A folio contains both maps and descriptive 

 matter. The price of folios ranges from 25 cents a copy to $1.00 a 

 copy, except that certain folios damaged by fire and water in 1913 

 are obtainable at 5 cents a copy. 



Geologic Atlas Sheets. Separate sheets forming a part of the 

 geologic folios are issued under this title in order to avoid the neces- 

 sity for supplying an entire folio when one or two sheets will meet 

 the requirements of persons desiring certain special data. The price 

 of each sheet is 10 cents. 



Special Geologic Maps. Only a few maps of this kind have been 

 issued. They are prepared in order to present conditions at some 

 particular place or in a way different from that employed in geologic 

 folios. The prices of the several special maps are listed in the pam- 

 phlets and index circulars above mentioned. 



Other Publications 



The remaining publications of the Survey, with the exception of 

 Monographs, may be obtained free from the Director of the United 

 States Geological Survey as long as the Survey's supply lasts. It is 

 possible then in some cases to purchase such publications from the 

 Superintendent of Documents, Government Printing Office, Washing- 

 ton, D. C. All Monographs are obtainable only from the Superin- 

 tendent of Public Documents and at prices stated. 



These publications of the Survey are listed in a large pamphlet en- 

 titled, "The Publications of the U. S. Geological Survey," the latest 

 volume of which was issued in December, 1916. This pamphlet is 

 supplemented from time to time by the issue of circular lists of new 

 publications. These publications are: 



Mineral Resources of the United States 

 Technical treatises on geologic and related scientific subjects 

 Monographs 

 Professional Papers 

 Bulletins 

 Water Supply Papers 

 Annual Report of Director 

 Miscellaneous 

 Mineral Resources of the United States. Each year the Survey 

 issues one or two volumes entitled "Mineral Resources of the United 

 States." These publications are, on request, distributed gratuitously 

 as long as the Survey's stock lasts. 



Technical Treatises on Geological and Related Scientific Subjects. 

 These publications are classified as Bulletins, Professional Papers, 

 and Monographs, the line of demarcation being based upon the ex- 

 tensiveness and exhaustiveness of the work. The Bulletins and Pro- 

 fessional Papers are distributed gratuitously as long as the Survey's 

 stock lasts. The Monographs are sold at prices ranging from eighty 

 cents up. 



Reference has been made in Chapter II to the tourist guide-books 

 of the western United States issued for the first time in 1915 and 

 listed under the title of Bulletins. Like other Bulletins these guide- 

 books are distributed gratuitously as long as the Survey's supply lasts. 



