CERATOPS BEDS OF WYOMING AND MONTANA 24I 



investigation in the field and during the present season several impor- 

 tant areas will be critically studied with special reference to evidence 

 of unconformities and the stratigraphic relations of faunas and floras. 

 In order to present somewhat in detail the data now in hand it will be 

 necessary to give a brief review of the stratigraphy and paleontology of 

 some of the more important areas preparatory to the general discus- 

 sion of the evidence. 



Local Stratigraphy and Paleontology. 



Converse County, Wyoming. — This area in Eastern Wyoming was 

 made famous 20 years ago by Hatcher's collections of the Triceratops 

 fauna, including the dinosaur genera Triceratops, Diceratops, Toro- 

 saurus, and Trachodon, together with turtles and other reptiles, fishes 

 and many small mammals. Hatcher's excellent descriptions^ of the 

 stratigraphy and general features of the region have been supple- 

 mented by Stanton and Knowlton's stratigraphic and paleontologic 

 notes' and much of this material has been republished in Hatcher 

 and Lull's Ceratopsia monograph.* The lowest member of the sec- 

 tion exposed is formed by the upper part of the Pierre shale with 

 abundant characteristic invertebrate fossils. This grades upward 

 into sandstones that have been referred to the Fox Hills including at 

 the top a massive bed of yellowish gray friable sandstone 100 feet 

 thick with concretions containing Veniella humilis, Sph(Eriola, Ger- 

 villia subtortuosa and other Fox Hills fossils. No marine fossils have 

 been found above this horizon. 



Sandstones mostly of light colors with very few and thin intercala- 

 tions of shale continue upward for 400 feet. This member has yielded 

 no fossils and may belong either to the Fox Hills or to the overlying 

 ''Ceratops beds" in which Hatcher originally included it. 



In the fossiliferous "Ceratops beds" there is no striking lithologic 

 change but there is a larger proportion of shale, a more rapid alterna- 



' Hatcher, J. B.: The Ceratops beds of Converse County, Wyoming. Am. 

 Jour. Sci., 3d ser.. Vol. XLV, 1893, pp. 135-144. Some locahties for Laramie 

 mammals and homed dinosaurs. Am. Naturalist, Vol. XXX, 1896, pp. 

 1 12-120. 



* Stanton, T. W. and Knowlton, F. H.: Stratigraphy and paleontology of 

 the Laramie and related formations in Wyoming. Bull. Geol. Soc. America, 

 Vol. VIII, 1897, pp. 128-137. 



*Mon. U. S. Geol. Survey, Vol. XLIX, 1907. 



