PREFATORY NOTE 



U. S. Geological and Geographical 



Survey of the Territories, 



Washington, August 1, 1877. 



Bulletin ISTo. 4, series of 1877, completes Volume III; and with this 

 number are issued index, title-page, table of contents, list of illustra- 

 tions, &c., for the whole volume. It is hoped that the separately pub- 

 lished numbers are preserved for binding, as there is no issue of the 

 Bulletins in bound volumes from this office, and as back numbers cannot 

 always be supplied to complete deficient files. 



In concluding the third volume of Bulletins, a word regarding the 

 origin and progress of this publication will not be out of place. The 

 issue began in 1874, when it was found desirable to establish more ready 

 means of communication with the public and with scientific bodies than 

 the regular Reports of the Survey afforded; the design being. to publish, 

 without the delay incident to the appearance of more elaborate and 

 extended articles, such new or specially interesting matter as should be 

 contributed to the general results of the Explorations under my charge 

 by the members or the collaborators of the Survey. The practical im- 

 portance of prompt measures in such cases is well recognized, and 

 sufficiently attested by the success which the Bulletins have achieved. 



The First and Second Bulletins, which appeared in 1874, are separately 

 paged pamphlets, without ostensible connection with each other or with 

 subsequent ones, but together constituting a "First Series" of the 

 publication. Bulletins which appeared in 1875, being those of a "Second 

 Series" and six in number, are continuously paged. With No, 6 were 

 issued title, contents, index, &c., for all the numbers of both " series " 

 which had then appeared; the design being that these should together 

 constitute a Volume I, in order that the inconvenient distinction of 

 "series" might be dropped. 



With Bulletin No. 1 of 187G, the publication was established as an 

 annual serial; the four consecutively paged numbers of that year con- 

 stituting Volume II. 



The four Bulletins of 1877 constitute Volume III, which compares 

 favorably with its predecessors in the extent, variety, and importance 

 of its contents, and is greatly improved in typography and general 

 appearance. 



Should no unforeseen circumstance prevent, the Bulletins will continue 



III 



