78 REPORT OF THE SECRETARY. 



in Colorado clearing up some doubtful points on the Sauropoda, on 

 which he is preparing a volume. Interesting collections were made of 

 mammals from the Jurassic of Wyoming, and some important speci- 

 mens were secured from the Tertiary of Oregon. Field work was 

 brought to a close in Oregon in October, but in Wyoming and Colorado 

 it was continued until late in the year. 



Work of Mr. C. D. Walcott. — Mr. Walcott's studies have been devoted 

 mainly to the invertebrate fossils of the Paleozoic age. During the 

 summer, he made an examination of the Potsdam and Calciferous forma- 

 tions in New York, for the purpose of comparison. He also examined 

 the Phillipsburg section of the Canadian Geological Survey, situated 2 

 miles north of the Vermont State line. The Cambrian strata of Frank- 

 lin County, New York, were also investigated, and the outcrop of lime- 

 stone at Greenfield, N. Y., was visited. Large collections were made 

 and full notes taken in regard to the complicated geological structure 

 of the regions examined. His office work has been mainly the study 

 of the Paleozoic fossils from near Eureka, Nev., and the preparation of 

 a map and section illustrative of the geology of the Grand Caiion of the 

 Colorado east of the Kaibab Plateau in Arizona. He has also prepared 

 the paleontologic portion of the Report on the Eureka district, which 

 will be published as Part II of Mr. Hague's report. It will include the 

 data obtained from the White Pine district. 



Work of Dr. G. A. White. — Dr. C. A. White is in charge of the study 

 of the invertebrate fossils from the Mesozoic and Tertiary formations. 

 He began field work, with Mr. J. B. Marcou as assistant, early in July r 

 making Fort Benton, in Montana, his outfitting point. Thence he pro- 

 ceeded eastward down the Missouri River to the mouth of Judith River, 

 where a special examination was made of the Judith River group. At- 

 tention was given also to the structure of the mountains in the vicinity 

 and to drift phenomena. The central and piir<cipal mass of the mount- 

 ains was found to be a trap rock different in stri cu e from that found 

 in the Rocky Mountains in Colorado. Moccasin Mountain and Square 

 Butte were found to be trachytic with stratified rocks flexed against 

 them. Bear Paw Mountain was found to be essentially the same. The 

 northern drift was found near the latter. Returning to Fort Benton, 

 Dr. White was joined by Prof. L. F.Ward, and after an examination of 

 several localities in that neighborhood, including the Great Falls of the 

 Missouri, they together descended the Missouri River in a boat from 

 Fort Benton, Mont., to Bismarck, Dakota. Only the Laramie group was 

 noted in this distance, and large collections were made. Later in the 

 season the Cretaceous strata near Sioux City were examined. 



Office work has been confined mainly to the study of the collections 

 and the revision of the text and illustration of a memoir on the " Os- 

 treidse of North America." Progress was made also in the preparation 

 of paleontologic bibliography. Mr. Marcou has devoted considerable 

 time to the arrangement and cataloguing of the Jurassic fossils for study 

 and revision, and has also prepared for publication a catalogue of maps. 



