24 BUREAU OF AMERICAN ETHNOLOGY 



will be inundated when the reservoir is flooded, were found. The 

 results of the work there confirmed the conclusions of the members of 

 the United States Geological Survey who had mapped the structure 

 and stratigraphy of that area. 



From July 14 to August 19 the Oligocene and Miocene deposits in 

 the Canyon Ferry Keservoir area on the Missoiu'i Kiver north of 

 Townsend, Broadwater County, Mont., were prospected for fossils. 

 Material was obtained from three localities in the Oligocene and two 

 in the Miocene. All those localities will be inundated. 



After the close of the work at Canyon Ferry, White's party pro- 

 ceeded to the Angostura Reservoir on the Cheyenne River in Fall 

 River County, S. Dak., to make a physiographic study of the area in 

 connection with an early-man site. The period from August 21 to 

 September 3 was spent in collecting data for that study. The party 

 returned to Lincoln, Nebr., on September 4 in order to prepare a 

 preliminary report on the results of the physiographic study. 



From September 23 to October 1 the Upper Cretaceous Carlile 

 Shale in Cedar Bluff Reservoir on the Smoky Hill River south of 

 Wakeeney, Trego County, Kans., was prospected for vertebrate fossils. 

 Although a number of specimens were found, they were so badly 

 disintegrated by the crystallization of gypsum and the weathering of 

 marcasite that they were not worth collecting. 



About 70 specimens, representing 20 genera, were obtained in the 

 Boysen Reservoir area. Although the specimens were for the most 

 part rather fragmentary, they were sufficiently well preserved to estab- 

 lish the age of those beds as belonging to the Lost Cabin faunal zone 

 of the lower Eocene, a fact that had not previously been demonstrated. 

 In the material obtained is the most nearly complete skull yet found of 

 the primitive insectivore, Didelphodus. Although badly crushed and 

 not impressive to look at, it adds a number of previously unknown 

 details to the knowledge of the cranial morphology of that form. 

 Also the skull and jaws of DidymictiSj a primitive carnivore a little 

 larger than a fox, was obtained in that area. Heretofore the form was 

 known only from upper and lower dentitions. 



Nearly 125 specimens, principally insectivores, rodents, and smaU 

 artiodactyls, were obtained in the Canyon Ferry Reservoir area. 

 Most of the specimens were found in the Oligocene deposits which 

 previously were very poorly known. The material obtained demon- 

 strated that deposits of both lower and middle Oligocene age were 

 present in that area. One of the Oligocene insectivores belongs to a 

 problematical family previously unknown in deposits later than the 

 upper Eocene. Also, it is the best-preserved specimen yet found and 

 adds many details of the skull and dentition to the knowledge of that 

 group. The small Oligocene mammals of that area, when compared 



