REPORT OF THE DIRECTOR OF THE GEOLOGICAL BUREAU. 391 



district the work comprised the survey of the Elk Mountain district, a completed 

 map of the neighborhood of Denver, and continuation of the surveys of the Yel- 

 lowstone Park, and the southern plateau region. 



In the great basin district a detailed map has been made of the, hydro- 

 graphic basin of Mono Lake for the purpose of exhibiting its remarkable" glacic 

 and volcanic features. Besides carrying forward the general survey of the Pacific 

 region, Mr. Thompson has begun and nearly completed a detailed map of Mount 

 Shasta. A field map covering about 24,000 square miles in northern California 

 is now ready for the use of geologists. The survey of the quicksilver districts of 

 California has been completed and detailed maps of several districts constructed. 



In geology, Mr. Hague and his assistants have been making a systematic 

 investigation of the physics of geyser action in the Yellowstone Park and study- 

 ing other natural phenomena. Dr. Hayden has been making a series of examin- 

 ations along the line of the Northern Pacific Railroad, and initial steps were taken 

 for a study of the natural waters of Montana. 



Dr. Peale has carried forward the preparation of a bibliography of the thermal 

 springs of the United States. Prof. Chamberlin has been studying glacial phe- 

 nomena. Prof. Roland Irving has been classifying the archsean rocks, and Mr. 

 Israel Russell has continued and completed the field examinations of the basin of 

 Mono Lake. Mr. Diller has visited Mount Shasta and the southern portion of 

 Cascade Range in connection with the survey of that range. Mr. McGee has 

 made a thorough geological reconnaissance from the District of Columbia as a 

 center of the interesting zone extending from the upper Hudson to the James 

 River. Mr. Emmons has practically completed the field work in the Silver Cliff 

 district of his economic studies in Colorado, ane will now proceed to the study 

 of the Gunnison region. At present his attention has been turned to problems 

 connected with the water supply of Denver. Mr. Becker has continued his 

 investigation of the quicksilver mines of California and has completed his field 

 work. 



While supervising the collection of palseontologic matter, Prof. Marsh has 

 given attention chiefly to the study of the material already accumulated, and the 

 preparation of monographic reports. His last memoir described a remarkable 

 order of birds furnished with teeth, and one now in press describes an order of 

 extinct mammals, the Dinocerata. A third, which approaches completion, treats 

 of the Saurpoda, an extinct reptilian order, several species of which were of 

 gigantic size. Dr. White has continued his studies of the invertebrate fossils of 

 the latter geologic ages, following the Missouri River for 1,000 miles in a row- 

 boat. Mr. Ward has undertaken the preparation of a bibliography of palaso- 

 botany. In chemic work, a laboratory has been established to meet a demand 

 for the determination of chemic problems. The physical investigations by Dr. 

 Carl Barns have been continued chiefly with a view to the measurement of high 

 temperatures. He has also continued an investigation on the conditions of sub- 

 sidence of very fine particles suspended in liquids, a subject of great geologic im- 

 portance. 



