made during several field trips in the United States and Canada, 

 as well as on an extensive series of casts of European specimens. 



During July and August, Curator Denison, accompanied by 

 Orville L. Gilpin, Chief Preparator of Fossils, prospected in the 

 Rocky Mountains from Alberta and British Columbia south through 

 Montana and Idaho to Utah and Wyoming (see page 36). The 

 northern part of the trip was largely reconnaissance with the purpose 

 of determining whether the Devonian formations showed promise 

 of yielding any good fossil-fish assemblages. In Idaho, the Devon- 

 ian Water Canyon formation was traced northwards from the out- 

 crops in Utah that were worked in 1949 and 1950. Important 

 additions to the fauna were made, including the first articulated 

 fishes that have come from this formation. The last few days of 

 the trip were spent at a new Devonian locality in the Bighorn 

 Mountains of Wyoming. The abundant and well-preserved mate- 

 rial obtained has prompted plans for future work here. 



William D. Turnbull, Assistant Curator of Fossil Mammals, 

 studied the collections of Washakie formation mammals from 

 Wyoming and spent ten days in the Carnegie Museum at Pitts- 

 burgh in this connection. He continued his work on the mam- 

 malian masticatory apparatus of the insectivore Echinosorex, and 

 with Dr. Charles A. Reed (University of Illinois) he studied two 

 new specimens of the early Oligocene insectivore Arctoryctes. Of 

 the numerous rodent specimens of the Washakie fauna that have re- 

 ceived special attention, a highly specialized small jumping rodent 

 Protoptychus appears to have had a dominant role. In the lab- 

 oratory, assisted by Burton Adlerblum, a graduate student from 

 the University of Chicago, he sorted out a goodly number of the 

 fossil mammal-teeth from the concentrates taken from ant hills in 

 the lower Washakie beds. He returned with Preparator Ronald J. 

 Lambert to the Washakie basin for six weeks of collecting in the 

 Eocene beds in June and July (see page 36). Noteworthy finds 

 were an articulated skeleton of the little rodent Protoptychus and 

 a uintathere skull. 



Albert W. Forslev, Associate Curator of Mineralogy, pursued 

 his study of the mineralogical and chemical composition of sedi- 

 ments and sedimentary rocks. Much of his time was devoted to 

 the investigation of the minerals making up the clay-sized fraction 

 of these materials. These "clay minerals" occur as crystals less 

 than one ten-thousandth of an inch in diameter and X-ray diffrac- 

 tion techniques are necessary for their identification. Among the 

 materials investigated were black shales from the Mecca quarry, 

 lake and swamp clays, and soils. He co-operated with Chief Cura- 



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