252 STANTON 



beds" rather than to the Fox Hills. No discordance has been 

 observed here at their base. Leonard's section records 535 feet of 

 shales and sandstones above the Pierre. 



Pierre shale is exposed in a similar uplift west of Forsyth. Doctor 

 Knowlton and I examined this section in 1908 near Castle Butte about 

 7 miles northwest of Forsyth, where we collected the following inverte- 

 brates: 



Inoceramus sagensis Owen? 



Trigonarca {Breviarca) exigua M. & H. 



Lcda (Yoldia) evansi M. & H. 



TJietys? circular is M. & H. 



Solemya? sp. 



Mactra gracilis M. & H. 



Corbidamella gregaria M. & H. 



Aniauropsis paludina'formis M. & H. 



Anchura nebrascensis M. & H. 



Fasciolaria {Piestochilus) cretacea M. & H. 



Bacidities compressus Say 



Scaphites nodosiis Owen 



Placenticeras whitfieldi Hyatt 



Placenticeras inter calare M. & H. 



Above the Pierre are yellowish cliff-forming sandstones with thinner 

 beds of shale dipping about 5° east which form the mass of Castle 

 Butte and other conspicuous hills in the neighborhood. There is an 

 estimated thickness of about 100 feet of these sandstones beneath the 

 rocks that form the bluffs at Forsyth where the beds are horizontal. 

 The contact between the Pierre shale and the overlying sandstone is 

 very well exposed and shows beneath the massive cliff forming sand- 

 stone, a few feet of soft sandstone alternating with clay shale appar- 

 ently forming a transition zone. 



Mr. A. C. Silberling informs me that at and near Castle Butte he 

 has observed remains of Triceratops, Claosaurns [Trachodon?], mam- 

 mals, turtles, and fishes, showing that the sandstones belong to the 

 " Ccratops beds. " He also reports the occurrence of Triceratops four 

 miles north of Rosebud on Horse Creek east of Forsyth and near 

 Junction City and Custer. 



The marine Cretaceous extends in a belt several miles wide from 

 Castle Butte across country along the line of the Chicago, Milwaukee 

 and St. Paul Railway, to Musselshell River, and uj) the Yellowstone 

 to a point one mile west of JNIyers station, which is about 30 miles west 



