120 



The names of the fossils collected from this sandstone are 

 prefixed by a star in the general table of fossils from the 

 Grand Tower formation, given on a later page. 



The following is a section of the Grand Tower strata ex- 

 cellently exposed in the Backbone-Bake-oven ridge, a short 

 distance north of the town of Grand Tower. The lower part 

 was made from the north and west sides of the Bake-oven 

 bluff, while the middle and upper portions were taken from 

 the west face of the Backbone ridge, one-half mile further 

 south. The section bears the field number S 56, and begins 

 wnth "a" at the bottom. The total thickness of strata exposed 



here is about 129 feet. 



S 56 a. Bed of coarse grained, gray, crystalline limestone, in 

 layers six to eighteen inches thick, somewhat arenaceous in the lower 

 part. To the level of the water in the river 8 feet. 



Dendropora neglecta r, Rhipidomella cf. niusculosa r, 



Ambocoelia umbonata r, Rhipidomella liz-ia c, 



Atrypa reticularis r, Rhipidomella sp. r, 



Camarotoechia cf. Carolina c, Schizophoria propinqua r, 



Centronella glansfagea r, " Spirifer cf. disparilis r, 



Chonetes mucronatus r, Spirifer duodenarius r, 



Dalmanella sp. r, Spirifer macrothyris c, 



Leptaena rhomboidalis c, Spirifer macrus r, 



Leptostrophia perplana r, Stropheodonta concava c, 



Meristella cf. lenta c, Stropheodonta demissa r, 



Nucleospira concinna c, Strophonella ampla c, 



Nucleospira ventricosa r, Platyceras cariiiattim r, 



Pholidops hamiltonae r, Platycenas erectum c, 



Productella sp. r, Platyceras dumosum r, 



Plaiyostoma sp. r. 



S 56 b. Alternating and somewhat mixed layers of gray, crystalline 

 limestone, and of rather coarse grained sandstone, the sandstone ele- 

 ment somewhat predominating 7 feet, 6 inches. 



Coscinium cribriforme r, Rhipidomella vanuxemi c, 



Atrvpa reticularis c, Spirifer duodenarius c, 



Centronella glansfagea c, Spirifer intermedius r, 



Charionella scitula r, Spirifer macrothyris r, 



Chonetes mucronatus r, Spirifer macrus r, 



Dalmanella tenticularis r, Stropheodonta sp. r. 



Eatonia? sp. r, Strophonella ampla r, 



Leptaena rhomboidalis c, Tentaculites scalariformis r, 



Meristella lenta c, Platyceras cannatum r, 



Platyceras erectum c 



S 56 c. Bed of gray, granular, sub-crystalline limestone, fossils 

 most abundant in the lower part, an iron, stained zone present at 

 the top 4 feet. 



Coscinium cri!>riforme r, Spirifer cf. zaricosus r, 



Atrypa reticularis c, Stropheodonta inaequtradtata r, 



Centronella glansfagea r, Strophonella ampla c, 



Chonetes mucronatus r, Igoceras contcum r, 



Eatonia whitfieldif r, Platyceras erectum c, 



Leptostrophia perplana r, Platyceras caniuilHim r, 



Rhipidomella vanuxemt c, Platyceras thetis r, 



Spirifer duodenanus c. Platyostoma hneaia r, 



Spirifer intermedius r, Dalmanttes sp. c, 



Spirifer macrothyris c. Odontocephalus aegena a, 



Spirifer macrus r, Proetus sp. r, ; 



