FOX HILLS AND LOWER MEDICINE BOW 21 



Horizon 2 foet from basp yieldod marine invertebrates: 

 Cardium whitei Dall 

 Lunatia concinna Meek and Haydcn 

 Lunatia dakotensis Henderson 



Mactra sp 167 



Shale, gray, papery, and tiiinly bedded, soft sandstone; brackish-water species at 

 base: 



Corbicula fracta fracta (Meek) 

 Ostrea glabra arcuatilis Meek 



Ostrea sp 10 



Sandstone, gray, massive, resistant, coarse; shelis of brackish-water form near 

 middle : 



Ostrea sp 18 



Shale, gray , sandy 3 



Coal bed 4 



Shale, gray, sandy 12 



Sandstone, grayish-brown, concretionary, fine-bedding. Hancock reported the 

 following brackish-water and marine species from this "lower massive sand- 

 stone":' 



Anomia micronema Meek 



Cardium speciosum Meek and Hayden 



Ostrea glabra Meek and Hayden 



Scaphites? sp. 



Sphenodiscus lenticularis (Owen)? 



Tellina scitula Meek and Hayden 110 



Shale, gray, sandy, with irregular lenses of grayish-brown, massive, fine-grained 

 sandstones; horizon at top yielded brackish-water species: 

 Anomia micronema Meek 

 Ostrea glabra glabra Meek and Hayden 



Ostrea sp 52 



Shale, gray, sandy, interbedded with three 1-foot layers of fine-grained quartzitic, 

 gray sandstone; marine species at base: 



Acteon attenuatus Meek and Mactra warrenana Meek and Hay- 



Hayden den 



Anomia sp. Pholadomya sp. 



Baculites sp. Pteria sp. 



Cardium whitei Dall TelHna scitula Meek and Hayden 



DentaUura sp. Thetis circularis Meek and Hayden 



Legumen planulatum Conrad Yoldia evansi Meek and Hayden 26 



Sandstone, grayish-brown, massive, fine-grained, resistant, with scattered remains 



of Halymenites 24 



Shale, gray, papery, grachng down into more sandy, thinly bedded shales; horizon 

 5 f eet f rom top yielded f resh-water species : 



Campeloma nebrascensis nebrascensis Meek and Hayden 

 Unio cf. U. priscus priscus Meek and Hayden 



Unio sp 35 



Sandstone, gray, concretionary, resistant, with 1-foot lenses of finer-grained, gray 

 sandstone at base containing marine species: 



Anatina sulcatina Shumard Dosiniopsis sp. 



Anchura sp. Micrabacia americana Meek and 



BacuUtes sp. Hayden 



Cardium sp. Tellina scitula Meek and Hayden _20 



Total Fox Hills formation 481 



Lewis shale: 



Gray, soft, clay shales, in part papery, in part sandy. Thickness not measured. 

 ' Hancock, E. T., U. S. Geol. Survey BuU. 757, 22, 1925. 



