PRELIMINARY HANDBOOK OF THE DEPARTMENT OF GEOLOGY. 11 



is in no case allowed to become destroyed. The more importaut collec- 

 tions in this study series are mentioned below : 



Systematic study series. — This collection comprises some three thou- 

 sand specimens of miscellaneous rocks from all parts of the globe, classi- 

 fied systematically as in the exhibition series. 



The Ixadville collection. — This comprises some threehundred and eighty 

 eruptive, sedimentary, and metamorphic rocks and ores as collected and 

 studied by Messrs. S. F. Emmons and C. Whitman Cross, of the U. S. 

 Geological Survey, from the vicinity of Leadville, Colorado. It is a 

 representative collection of the material described by the above-named 

 authorities in Monograph xn of the U. S. Geological Survey, J. W. 

 Powell, Director, and entitled " Geology and Mining Industries of Lead- 

 ville." A characteristic series of the rocks and ores has been selected 

 out and placed upon exhibition in the section devoted to economic ge- 

 ology. (Catalogue Nos. 68801-69540 inclusive.) 



The Washoe collections. — These collections represent the work done 

 by G. F. Becker and colleagues in the Washoe District and Comstock 

 Lode, Nevada, the results of which were published in Monograph in of 

 the II. S. Geological Survey, entitled " The Geology of the Comstock 

 Lode." They have also been the subject of investigation by Messrs. 

 Hague andlddings of the Geological Survey, whose results are embod- 

 ied in Bulletin No. 7, IT. S. Geological Survey, 1885, entitled "The De- 

 velopment of Crystallization in the Iugeous Rocks of Washoe, Nevada." 

 The collection is in part duplicated. There is first a series of 198 spec- 

 imens typical rocks of the region in sizes some 4 by 5 by 1 inch, and 

 second, the main study series in sizes about 1£ by 1 by 1\ inches, and 

 comprising 2,064 specimens. (Catalogue Nos. 24001-24198 inclusive 

 and 70691-72754 inclusive.) 



The collections of the Fortieth Parallel Survey. — This comprises some 

 three thousand specimens of eruptive and sedimentary rocks collected 

 by members of the Fortieth Parallel Survey, under the direction of Clar- 

 ence King in 1867-'73. The eruptive rocks of the series were described 

 by Prof. F. Zirkel in Vol. vi (Microscopic Petrography) of the Reports 

 of the U. S. Geological Explorations of the Fortieth Parallel. (Catalogue 

 Nos. 20301-23398 inclusive.) 



The Ha ices collections. — These comprise some 350 specimens eruptive 

 aud altered rocks representing in part the work done by Dr. Hawes in 

 connection with the New Hampshire surveys as published in Part iv, 

 Vol. in, of these reports. It also includes the small fragments de- 

 scribed in his paper on the Albany granites and their contact phenom- 

 ena. (Am. Jour, of Science, 1881, xxi, p. 21-32 ; Catalogue Nos. 29628- 

 29290.) 



The Pacific Slope quicksilver collections. — These comprise several hun- 

 dred small specimens (mostly 4x6 c m) rocks and ores from the quick- 

 silver regions of the locality above noted, as collected and described by 



