88 LAKAMIE BASIN, WYOMING. 
reports. One mile northwest of Harpers there is an exposure of white sandstone with 
clays and coal seams, showing a total thickness of about 40 feet and dipping from 9° to 
10° S. Fossil plants are abundant near the base of the exposure and are common in a 
band 20 to 25 feet higher, but the number of species represented is not large. They 
are interesting, however, from the fact that they are of certainly lower Laramie types 
or even older. The following is the list: 
Sequoia reichenbachi (?) Gein. I Anemia subcretacea (Sap.) Gard. and Ett. 
Brachyphyllum n. sp. | Cinnamomum affine Lx. 
The beds immediately overlying the coal-bearing series are usually covered, con- 
sisting apparently of soft clay shales. A fortunate exposure about 200 yards south of 
the plant-bearing locality, and consequently little more than 100 feet higher, shows a 
few feet of such clays with harder bands and concretions that have yielded the follow- 
ing characteristic Cretaceous species: 
Chlamys nebrascensis M. and H. 1 Baculites ovatus Say. 
Inoceramus cripsii var. barabini Morton. | 
These species occur in both the Fort Pierre and the 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 our 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, extend- 
ing westward several miles toward Rock Creek from a point about 1 mile west of 
Harpers. The light-colored sandstones associated with the coal are here exposed to a 
thickness of about 75 feet, dipping 17° S. and forming a prominent line of cliffs. In 
the upper part of the exposure, at a locality about 5 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 fossil iferous horizon in brown and gray sandstone from 500 to 
600 feet above the plant zone and apparently conformable with it. The following 
Montana species were obtained here: 
Baculites compressus Say. 
Scaphites sp. 
Ostrea sp. 
Avicula nebrascana E. and S. 
Baculites ovatus 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 between the Fort Pierre and the Fox 
Hills, and it is usually more convenient, as well as safer, to speak of them collectively 
as the Montana formation. 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. 
