36 AN"NUAL EEPORT SMITHSONIAN" INSTITUTION, 19 31 



the trip. Later m the year Mr. Henderson made a brief trip to some 

 of the noted mineral localities in North Carolina to obtain material 

 needed for the study of particular problems. 



Dr. C. E. Resser spent about four months in the field, working 

 first in the Grand Canyon, in Arizona, under the auspices of the Car- 

 negie Institution. The second phase of his work led diagonally 

 across the State of Arizona on a rapid reconnaissance, followed by a 

 return to the Grand Canyon for further studies. In this he was 

 accompanied by Dr. A. A. Stoyanow, of the University of Arizona, 

 and by members of the Park Service, who aided in his investigations. 

 Early in July, starting from Salt Lake City, where Dr. R. Endo 

 became a member of the partj^, work began on the local geology 

 about Delta, Utah, where the party was accompanied by Frank 

 Beckwith, with a profitable visit to Zion Canyon. Thence the course 

 lay north to the Tetons and other places in the vicinit}'' of Yellow- 

 stone National Park. During investigations at those places. Dr. 

 and Mrs. Curt Teichert joined the party. Rain interfered mate- 

 rially with travel and work ; and since matters of moment requiring 

 attention arose at the Museum, work was closed for the season. 

 Travel from Salt Lake City was by truck, the entire trip home being 

 made by this means. The season as a whole was most profitable 

 in the knowledge gained of the various geologic strata, although not 

 many fossils were secured, as the strata studied are for the most part 

 nonfossiliferous. 



Since the field exploration in charge of C. W. Gilmore extended 

 into the present year, but brief mention was made of it in last year's 

 report. This exploration in the Bridger (Eocene), in the Bridger 

 Basin, southwestern Wyoming, met with unusual success in the 

 acquisition of large and representative collections. Some of the 

 outstanding specimens have been mentioned elsewhere in this report. 

 The collection as a whole gives the division a good representation of 

 the Bridger fauna and in all probability contains many undescribed 

 forms, being particularly rich in mammals. Its value was further 

 enhanced by the cooperation of Dr. W. H. Bradley, of the United 

 States Geological Survey, who secured the necessary data for a 

 large-scale map, which, with his geological sections, insures the ac- 

 curate placing of the specimens both geographically and geologically. 

 George F. Sternberg, as in pre^dous seasons, rendered efiicient serv- 

 ice, and George B, Pierce ably assisted as field assistant. At the 

 close of the fiscal year Mr. Gilmore, again accompanied by Mr. 

 Sternberg, was in the field in Montana and Wyoming. 



Although work at the fossil locality near Hagerman, Idaho, was 

 very successful in the season of 1929, the results of the 1930 expedi- 

 tion under Dr. J. W. Gidley exceeded it in both quantity and quality, 



