REPORT OF NATIONAL MUSEUM, 1925 87 



Chemical and optical investigations on the minerals carnotite, 

 hedyphane, and natrojarosite have been completed by Doctor 

 Foshag. A study of the ore deposits of the Pilot Mountains in 

 Nevada and of andalusite deposits in Mono County, Calif., have 

 also been finished. There are now in progress studies of the ore 

 deposits of the Hawthorne quadrangle, Nevada; of some mineral 

 cavities in volcanic rocks from Nevada; and of a new calcium 

 vanadate from Utah. 



Paleontological researches include Secretary Walcott's studies on 

 the stratigraphy of the Cambrian and associated formations of 

 British Columbia, covering many years of field work. Studies on 

 the same formations in the United States are under way. 



Dr. R. S. Bassler has completed the illustrations for his work with 

 Ferdinand Canu on the Recent Bryozoa of the Gulf of Mexico. He 

 has also, in collaboration with Doctor Ulrich, completed a mono- 

 graph on the fish-toothlike organisms known as conodonts from the 

 Devonian and Mississippian of America. It is believed by the 

 authors that this work will be as useful to future students as the 

 various papers on foraminifera published by the Museum. 



Dr. E. O. Ulrich has completed a .monograph of the trilobite genus 

 Leiostegium and its allies and a paper descriptive of 40 genera of 

 Cambrian and Ozarkian trilobites. In collaboration with Dr. 

 Charles E. Resser, he has continued work on the Cambrian of Wis- 

 consin. Doctor Resser has likewise assisted Secretary Walcott 

 throughout the year in paleontological studies. 



Dr. Frank Springer, whose work has been much retarded by ill- 

 ness, has nevertheless made good progress in his studies of the 

 Silurian crinoids of the Ohio Valley and hopes to complete his mono- 

 graph within the coming year. 



Dr. Mary J. Rathbun has completed a report on the fossil stalk- 

 eyed Crustacea known to occur on the Pacific slope of North America 

 from Alaska to California. The material used comprises all speci- 

 mens from the leading universities, museums, and private collections 

 on the Pacific coast, as well as those from the United States Geo- 

 logical Survey and National Museum. 



Dr. W. H. Dall has studied the Tertiary and Pleistocene collec- 

 tions of the Canadian Arctic expedition; has revised a manuscript 

 on the Lower San Pedro fauna of Nob Hill, Calif., for T. S. Old- 

 royd, the author; and studied and reported on a lot of dredged 

 fossiliferous bowlders from off the Atlantic coast, submitted by the 

 department of paleontology of Yale University. He reports the 

 most interesting discovery of the year to have been the finding of a 

 peculiar fresh- water fauna, hitherto represented only in the Balkan 

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