292 



FRANK A. WILDER 



about Fort Biiford. As exposed along the Cannon Ball River, the 

 Laramie is made up for the most part of sand and sandstone, while 

 lignite is present only in thin beds, and clay is second to sand in 

 abundance. Here, however, Corhiciila nehraskensis M. & H. is found 

 in abundance, which was originally reported from the Fort Union 

 of the Northwest. 



Shells were found in abundance at a number of points, the fol- 

 lowing forms being frequently noted: 



Viviparus frochiformis M. & H. 



Campeloma multilineata M. & H. 



Unio prise us M. & H. 



These were found alike about old Fort Union and in the Laramie, 

 and at various horizons. 



At a number of points leaf-prints were found. Ten miles north 

 of Minot and one hundred and twenty miles east of old Fort Union, 

 a clay bed between two lignite seams occurs, tilled with the following 

 forms : 



Sequoia angustifolia Lesq. 



Sequoia Langsdorfli (Brongniart) Heer. 



Sequoia brevi folia Lesq. 



At least one of these forms was found at Mannhaven, eighty miles 

 north of Mandan. Though the Fort Union has never been definitely 

 outlined, no one seems to have extended it to these points. In these 

 two localities the leaf-prints had a nearly common elevation of 1,600 

 feet, while the lowest beds exposed on the Missouri River at old 

 Fort Union are 1,800 feet above the sea. 



Near Coal Harbor, which is eighty miles north of Bismarck, at 

 an elevation of 100 feet above the Missouri River, and both outside 

 of and below the Fort Union beds, as they are commonly understood, 

 a limestone layer about two feet thick occurs, which abounds in leaf 

 prints. From this hmestone the following were taken: 



Credneria ? daturiae folia. 



Phyllites cupanioides Newb. 



Celastrus (probably). 



In his note returning the fossils, Mr. R. S. Bassler, of the U. S. 

 National Museum, to whom the specimens were sent, says: "Mr. 

 Knowlton, of the United States Geological Survey, has kindly identi 

 fied them, and says that their age appears to be Fort Union." 



