138 STANTON & KNOWLTON — LARAMIE AND RELATED FORMATIONS. 



harder bands and concretions that have yielded the following character- 

 istic Cretaceous species : 



Chlamys nebrascensis, M. and H. Baculites oratus, Say. 



Inoceramus cripsii var. bambini, Morton. 



These species occur in both the Fort Pierre and Fox Hills beds, which 

 are not very clearly differentiated in this region, but the fauna of the 

 underlying beds shows that we are here probably in the Fox Hills beds. 

 Since oar return from the field Professor Knight informs us that he has 

 found a Fox Hills fauna fully a mile farther south and probably 1,000 

 feet higher than the plant-bearing horizon. 



This same coal and plant horizon is exposed on the west side of the 

 railroad extending westward several miles toward Rock creek from a 

 point about one mile west of Harpers. The light-colored sandstones 

 associated with the coal are here exposed to a thickness of about 75 feet, 

 dipping 17 degrees south, and forming a prominent line of cliffs. In the 

 upper part of the exposure, at a locality about five miles west of Harpers, 

 a few fossil plants were collected, including Sequoia reichenbachii (?) Gein, 

 and Cinnamomum affine, Lx. 



The stratigraphic relation of the plant bed to the overlying marine 

 strata was again confirmed by finding a fossiliferous horizon in brown 

 and gray sandstone from 500 to 600 feet above the plant zone and ap- 

 parently conformable with it. The following Montana species were 

 obtained here : 



Cstrea sp. Baculites compressus, Say. 



Avicula nebrascana, E. and S. Scaphites sp. 



Baculites ovalus, Say. 



The beds below the coal horizon probably belong to the upper part of 

 the Fort Pierre, but on the Laramie plains, as in many other regions, no 

 sharp distinction, either paleontologic or lithologic, can be drawn be- 

 tween the Fort Pierre and the Fox Hills, and it is usually more conven- 

 ient as well as safer to speak of them collectively as the Montana forma- 

 tion. These lower beds contain several fossiliferous horizons, two of 

 which are especially prominent, both on account of the number and 

 variety of their fossils and from the fact that they are in hard sandstones, 

 whose outcrops form narrow ridges that can be traced continuously for 

 several miles on both sides of the railroad near Harpers. Collections 

 were made from the upper of these horizons, which is from 400 to 500 

 feet below the coal, at several localities within the limits just indicated. 

 The list of species is as follows : 



