BITTER CREEK VALLEY — BLACK BUTTES. 143 



horizon at Point of Rocks, Wyoming, holds a similar position beneath 

 marine beds, as we shall show more in detail. 



Localities in Bitter Creek Valley. 

 bla ck b uttes. 



The stratigraphy and paleontology of Bitter Creek valle} r have been 

 discussed and described more frequently and by a greater number of 

 authors * than any other similar area that has been referred to the Lara- 

 mie. Besides being easily accessible and within the areas studied by 

 three of the geological survey organizations that were working in the west 

 20 years ago, it became important on account of the abundant and varied 

 paleontological material it afforded. The first Dinosaur (Agathaumas syl- 

 vestris) recognized in the Laramie was found at Black Buttes. The same 

 locality has yielded a large number of fossil plants and a greater propor- 

 tion of the described invertebrate species of the Laramie than any other 

 single locality. The other places along Bitter creek mentioned beyond 

 have also yielded plant and invertebrate fossils, and important coal beds 

 have been more or less developed at all three localities. 



The most prominent feature of the section at Black Buttes is the massive 

 bed of sandstone, somewhat over 100 feet thick at the base of the exposure, 

 forming steep hills and cliffs northeast of the railroad opposite the sta- 

 tion and passing beneath the surface by its dip of 9 or 10 degrees near 

 the coal mine. The upper portion of it is also exposed on the south side 

 of Bitter Creek valley, about a mile from the station. All of the Laramie 

 fossils, whether plants, invertebrates, or vertebrates, that have hitherto 

 been described or listed as coming from Black Buttes were obtained from 

 the overlying beds within about 100 feet of the top of this massive sand- 

 stone. The original specimen of Agathaumas sylvestris was found about 

 20 feet above it, and the plants that have been described came from the 

 same horizon and from several higher bands up to the bed overling the 

 principal coal, some 60 or 75 feet higher. The invertebrates from this 

 locality have about the same range. Most of the beds vary considerably 



* Hayden : Reprint of ist, 2d, and 3d Ann. Reports U. S. Geol. Survey Terr., pp. 99-100 ; Bull. 

 U. S. Geol. Survey Terr., vol. i, pp. 401-411, 1876. Cope : Proc. Am. Philos. Soc, vol. xii, 1872, pp. 

 481-483 ; Am. Naturalist, vol. vi, 1872, pp. 669-671 ; Ann. Rep. U. S. Geol. Survey Terr, for 1873, pp. 

 435i 436 ; Bull. U. S. Geol. Survey Terr., ist ser., no. 2, pp. 5-13. Meek : Ann. Rep. U. S. Geol. 

 Survey Terr, for 1872, pp. 455-456 ; U. S. Geol. Survey Terr., 4 , vol. ix, pp. li-lv, 1876. Bannister : 

 Ann. Rep. U. S. Geol. Survey Terr, for 1872, pp. 526, 527, 535. Lesquereux : Idem for 1873, p. 373 ; 

 Idem for 1874, p. 285 ; Bull. U. S. Geol. Survey Terr., vol. i, 1876, pp. 233-248, 363-382 ; The Tertiary 

 Flora, 1878, pp. 25-31, 342-344, 347-352. Powell : Geology of the Uinta Mountains, pp. 45-49, 162-166, 

 1876. Emmons : U. S. Geol. Expl. 40th Parallel, vol. ii, 1877, pp. 227-236. King : Idem, vol. i, 1878, 

 PP- 33 I- 337- White : Bull. U. S. Geol. Survey Terr., vol. iii, 1877, pp. 599-616 ; Ann. Rep. U. S. Geol. 

 Survey Terr, for 1877, pp. 215-224; Idem for 1878, pp. 49-103. Ward: 6th Ann. Rep. U. S. Geol. 

 Survey, 1886, pp. 539, 540. 



XXI— Bull. Geol. Soc. Am., Vol. 8, 1896 



