;68 



F. H. KNOWLTON 



formation may be briefly alluded to. It appears that in the 

 hundreds of localities throughout the Dakotas, Wyoming, and 

 Montana at which the contact between Fox Hills and the Lance 



Figs. 2, 3. — Eastern part of Custer County, Montana, showing erosional uncon- 

 formity between Fox Hills and Lance. Photographs by Bowen. 



formation has been examined, only five localities, all within a 

 limited area in South Dakota, have been noted in which the marine 

 Fox Hills invertebrates occur above the acknowledged top of the 

 Fox Hills, where they are often found commingled with certain 



