REPORT OF THE SECRETARY 21 



for etching of Permian limestone from the Glass Mountains. Next, at 

 Alamagordo and Silver City, N. Mex., Devonian fossils were obtained, 

 and from here the party proceeded to Eureka, Nev., to join Dr. T. B. 

 Nolan, of the United States Geological Survey, in mapping the Good- 

 win formation in Goodwin Canyon. The Devonian and Lower Ordo- 

 vician beds of some of the ranges west of Eureka were visited and the 

 field work ended at Salt Lake City. 



Upon Dr. Cooper's return, Dr. A. R. Loeblich, Jr., was engaged for 

 6 weeks in collecting Ordovician fossils in southern Virginia and 

 eastern Tennessee, in the region west of Nashville, and the Silurian 

 and Devonian in the classic areas of the valleys of the Tennessee River 

 in west Tennessee. On a short detail in August 1946 he spent several 

 days conferring with Dr. William H. Shideler at Miami University, 

 Oxford, Ohio, and a like period collecting Middle Ordovician and 

 Lower Devonian fossils in the Arbuckle Mountains, Okla. In late 

 April 1947, at the invitation of the Oklahoma Geological Survey, he 

 was occupied for 2 weeks in that State on stratigraphic work examin- 

 ing and collecting from the Silurian and Lower Devonian of the 

 Arbuckle Mountains. 



In addition to the above field investigations, four short trips were 

 made by Drs. Cooper and Loeblich into the nearby Appalachians, 

 which resulted in good collections and blocks containing silicified 

 fossils for etching. The localities visited included the fine Middle 

 Ordovician exposures about 5 miles north of Harrisonburg, Va., the 

 Lower Devonian exposures on United States Highway No. 40 about 

 214 miles west of Indian Springs, Md., the Middle Ordovician at 

 Strasburg, Va., and the Silurian and Devonian at Keyser, W. Va., and 

 Cumberland, Md. 



The 1946 summer field expedition in vertebrate paleontology, start- 

 ing in late May, continued well into the present year. The party, 

 composed of Curator C. Lewis Gazin and F. L. Pearce, first reexam- 

 ined the Paleocene and Cretaceous beds of central Utah and then de- 

 voted the greater part of the field season to prospecting and collecting 

 fossil mammal remains from the Middle Eocene beds in the Bridger 

 Basin of southwestern Wyoming. Collecting from the Bridger for- 

 mation is part of a research program on the Middle Eocene faunas 

 begun prior to the war. As a result of these expeditions, the National 

 Museum is building up one of the best research collections of Middle 

 Eocene mammals in the country and has succeeded in obtaining some 

 striking exhibition material representing this very primitive stage of 

 mammalian evolution. The party was successful in getting much 

 good material of the smaller, less-well-known insectivores, primates, 

 rodents, carnivores, and artiodactyls, as well as good skulls of such 

 animals as Hyrachyus^ Palaeosyops^ and TJintatheriwm. 



