8 ANNUAL REPORT SMITHSONIAN INSTITUTION, 191*7. 



Lefroy, where the melting snows cascade down as a beautiful brook 

 over the quartzite ledges. 



At last, in the cliffs above Eoss Lake the AZb&rtella fauna was 

 located in situ, and from the slopes above the lake a panoramic view 

 was taken of Mount Bosworth, above Kicking Horse Pass on the 

 Continental Divide. Although only 9,083 feet in height, Mount Bos- 

 worth exposes in its slopes over 12,000 feet in thickness of bedded 

 rocks that constitute one of the best sections of the Cambrian rocks 

 found in the Canadian Rockies. 



Considerable collections of Cambrian fossils were obtained by 

 myself and Mrs. Walcott, who accompanied and worked with me 

 throughout the entire trip, before the storms of late September drove 

 us back to Banff and ended the research for the season. 



Many of the photographs taken in this wonderful region are repro- 

 duced in one of the publications of the Institution. 1 



GEOLOGICAL FIELD STUDIES. 



Dr. George P. Merrill, head curator of geology in the National 

 Museum, devoted several days of the summer vacation period in 1916 

 to visiting the gem and feldspar quarries of Auburn. Topsham, and 

 neighboring areas in Maine. While nothing new was secured, he 

 was able to add interesting material to the Museum exhibit illustrat- 

 ing the character and association of the pegmatite dikes, which is 

 now being installed in the Museum. 



HUNTING GKAPTOLITES IX THE APPALACHIAN VALLEY. 



The great value of the extinct organisms known as graptolites in 

 determining the age of geological formations which contain few and 

 often no other kinds of fossils, has been proved time and again. 

 During the summer of 1916 Dr. E. S. Bassler and Mr. C. E. Eesser, 

 both of the division of paleontology, United States National Mu- 

 seum, had occasion to test this particular group of fossils in the course 

 of a study of the Cambrian and Ordovician shale formations of 

 western. Maryland. They report that — 



Recent excavations along the Western Maryland Railroad, in the great shale 

 belt just west of Williamsport and extending north and south for hundreds of 

 miles, exposed these rocks to such advantage that it was thought possible 

 enough fossils could be found in them to determine tlieir exact geologic age and 

 structure 1 . However, no fossils of any kind were found after much search. It 

 was then decided that the rocks were either barren of organic life or the cleav- 

 age produced in the strata by the great forces resulting in their present folded 

 condition destroyed all traces of fossils. 



Finally a fold of black shale was observed and at the point where the 

 cleavage and the bedding planes coincided, abundant graptolite remains were 



1 Smithsonian Miscellaneous Collections, vol. 66, No. 17, 1917. 



