JTTBASSIC FOSSILS. 165 



Cretaceous. Feet. 



13. Sandstone, yellow, with red stains, containing strata of coarse conglomerate. 75 



12. Shales, dark gray, calcareous ; with impure limestone 5 



11. Sandstone, very soft and white, near top pinkish; massive in places ; contains 



layers of fine conglomerate 50 



Jura (580 feet). 

 10. Clay or marls, yellow, greenish, and gray, sometimes sandy, with streak of 



purple near top 140 



9. Sandstone, brown, lamellar 3 



8. Clay or marl, brownish and sandy 15 



7. Limestone, thin stratum, very fossiliferous ; from its equivalent in the vicin- 

 ity many fossils were collected — 



G. Clay or marl, yellow ; with red sandy clay at base; exposures not complete. 235 

 5. Sandstone, yellow, in places quite red, shaly at the top but lower part massive . 50-75 

 4. Clay or marl, gray and greenish, with pink streak near the middle; calcare- 

 ous at base, with much flint; in an impure limestone occur many fossils 120 



Red Beds. 



3. Sandstone, red and soft, with much gypsum 10 



2. Gypsum in layers of 12 inches, interstratified with red sandy clay for a space 



of 15-20 



1. Sandstone, or sandy clay, soft, red to bed of river. . 150 



No. 1 1 in this section will be seen to correspond in position and char- 

 acter with a sandstone in the section on Beaver Creek, and it is included 

 in the Cretaceous, although it has not the common character of the Dakota 

 sandstone. The fossiliferous stratum (in 7) is probably the same as the 

 upper fossiliferous stratum of the Redwater section. That stratum is 350 

 feet above the Red Bed; this, in a thicker series, is 50 feet higher. The 

 Belle Fourche locality yielded — 



Ostrea strigilecula. Tancredia corbuliformis. 



Avicula mucronata. Tancredia bulbosa. 



Trapezium Belief ourchensis. Tancredia postica. 



Pleuromya Ntwtoni. JDosinia Jurassica. 



Tancredia inomata. Ammonites cordiformis. 



At the base of the yellow calcareous clays (4) forming- the bottom of 

 the Jurassic series there is a calcareous layer containing many fossils. 

 Among them are — 



Ostrea strigilecula. Psammobia prematura 



Camptonectes bellistriatus. Belemnites densus. 



Pseudomonotis curta. 



