362 F. H. KNOWLTON 



rado. The Popidus above mentioned has not been found out- 

 side the Fort Union. Viburnum marginatum was described first 

 from Black Buttes, Wyoming, and has since been found in many 

 places, among them several localities in the Lance formation of 

 the Dakotas. The form identified as Sassafras? is a peculiar leaf 

 and is apparently the same as an unnamed form from the Lance 

 formation of Converse County. This analysis shows that three 

 of the five forms noted in this collection are found in the Lance 

 formation. 



About five miles south of the above-mentioned Triceratops 

 locality the "Upper Laramie" crosses the North Platte and the 

 exposures are excellent. At this point the "Upper Laramie" 

 consists of a great thickness of massive beds of yellowish and 

 whitish sandstone, with much cross-bedding and abrupt changes 

 from one color to another. Several hundred feet above the exposed 

 base of this section we obtained a small collection of plants which 

 embraces some three or four species, all of which are identical with 

 undescribed forms from the Lance formation of Montana and the 

 Dakotas. 



The evidence of the plants is thus seen to confirm that of the 

 vertebrates in correlating these beds with the Lance formation 

 of Converse County and other areas in Montana and the Dakotas. 



THE OLD STANDING ROCK AND CHEYENNE RIVER INDIAN 

 RESERVATIONS 



On the west side of the Missouri River, and lying between the 

 Cannonball River on the north and the Cheyenne River on the 

 south, is the area comprising in large part what was originally 

 within the Standing Rock and Cheyenne River Indian Reservations. 

 During the spring and early summer of 1909 this region was studied 

 by a number of parties from the U.S. Geological Survey under the 

 general charge of Mr. W. R. Calvert. The geology of this area 

 is comparatively simple, the rocks being very little disturbed and 

 at most comprising not more than four formations. Beginning 

 with the lowest these are the Pierre shale, which is exposed in the 

 valleys of most of the streams, and is overlain without strati- 

 graphic break by the Fox Hills, which is the highest marine forma- 



