12 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1<>21. 



of limestone, shales and sandstones occur in the break in sedimenta- 

 tion of Ghost River cliffs. 



Returning to Bow Valley, the party left the Canadian Pacific 

 Railroad at Lake Louise and went north over Pipestone Pass to the 

 Siffleur River, which is tributary to the Saskatchewan. In the north- 

 ward facing cliffs, 25 miles (40 kilometers) east of the Glacier Lake 

 section of 1919, and 40 miles (64 kilometers) north of Lake Louise, 

 a geological section was studied that tied in the base of the Glacier 

 Lake section of 1919 with the Middle and Lower Cambrian forma- 

 tions. Returning up the canyon valley of the Siffleur River to the 

 wide upper valley of the Clearwater River, a most perfectly exposed 

 series of limestones, shales, and sandstones of Upper Cambrian and 

 later formations was found, which cleared up the relations of the 

 upper portion of the Glacier Lake section to the Ordovician above. 



The work was considerably handicapped by forest fires in July 

 and August and by unusually stormy weather in September. 



IWLEONTOLOGICAL FIELD-WORK. 



Dr. R. S. Bassler, curator of paleontology, National Museum, suc- 

 ceeded during the year in securing for the Museum's collections two 

 much-desired specimens, one a large well-preserved fossil elephant 

 skull formerly exhibited in Cincinnati, the other a highly fossilifer- 

 ous limestone slab of Silurian age quarried out by him near Oxford, 

 Ohio. Such a slab has long been desired to show the advancement 

 in life from the primitive Cambrian forms, represented in the large 

 Cambrian sea-beach sandstone exhibit, to the higher and more com- 

 plex species of succeeding geological periods. Notwithstanding the 

 numerous occurrences of fossiliferous limestone of Ordovician and 

 Silurian age, it was not until the past year that a layer affording 

 slabs of suitable size and sufficient perfection of preservation was 

 brought to the attention of the Museum. Numerous large blocks of 

 stone had to be removed before the real task of quarrying the de- 

 sired slab was begun. The work was successfully accomplished with 

 the generous assistance of Dr. W. H. Shideler, professor of geology 

 at Miami University, Oxford, Ohio, who first located the specimen, 

 and before the close of the year this valuable educational exhibit 

 was installed in the hall of invertebrate paleontology. 



At the conclusion of this work Dr. Bassler proceeded to Chicago 

 for the purpose of securing casts of type specimens of fossils in the 

 collections of the Walker Museum, University of Chicago. Regard- 

 ing this work, Dr. Bassler says : 



The paleontological collection of the National Museum, which includes the 

 celebrated Walcott, Ulrich, Springer, Harris, Nettelroth, and Kominger col- 

 lections, is especially rich in type specimens of early Paleozoic fossils, but 

 nevertheless the Walker Museum possesses many unique types not represented 



