WARSAW GROUP ST. LOUIS GROUP. 71 



CHAPTER XXIX. 



\VARSAW QROUP. 



149. THIS Group was named from Warsaw, Illinois, by Hall, in 1856, and 

 more fully defined in 1858. At the typical locality, near Warsaw, it consists of 

 magnesian, arenaceous, and shaly limestones, abounding in Bryozoa. It is conform- 

 able with the Keokuk, only a few feet in thickness, and generally considered as 

 a member of the Keokuk. I have retained it, because so many small fossils have 

 been described from it, which have been the means of identifying it, at great dis- 

 tances from the typical locality. It occurs below the limestone of the cliffs at 

 Alton, Illinois; at Bloomington and Spergen Hill, Indiana; and in St. Genevieve 

 County, Missouri, where it attains its maximum thickness of 100 feet. It should 

 probably be regarded as a mere member of the Keokuk Group. Some of the fossils 

 having great distribution, and therefore characteristic, are Endothyra baileyi, Dicho- 

 crinus simplex, Alloprosalloerinus conicm, Batocrinus icosidactylus, Pentremites konincka- 

 nus, Productus biseriatus, Spiriferina norwoodana, Aihyris hirsute, Rhynchvnetta grosve- 

 nori, R. mutata, Terebratula turgida, T. formosa, Cypricardinia indianensis, Betterophon 

 sublcevis, Naticopsis carleyana, Holopea proutana, Cyclonema leavenworthanum, Pleur- 

 tomaria subglobusa, and Spirorbvs annulatus. 



CHAPTER XXX. 



ST. LOUIS OROUP. 



150. THIS Group was named and described by Dr. Shumard in the Geolog- 

 ical Survey of Missouri, in 1855. In St. Louis County it is celebrated for its 

 splendid quarries, and consists of hard crystalline limestone, sometimes cherty, with 

 thin layers of argillaceous shales, and has a maximum thickness of 250 feet. It 

 forms bluffs below St. Louis as far as Carondelet, where it dips beneath the Missis- 

 sippi, but soon rises again, and forms bluffs as far as the Meramec, some of which 

 are 175 feet high. It is exposed in the western part of Illinois and eastern part of 

 Missouri and Iowa, thinning out a short distance north of Keokuk. It forms a 

 band of red clay, chert, and limestone bordering the Indiana coal-fields, and 

 crosses Kentucky and Tennessee, south, by way of Clarksville. It borders the Ap- 

 palachian coal-field in Southern Kentucky, and may be seen at Burnside, on the 

 Cincinnati Southern Railroad and in Eastern Kentucky. In Indiana it consists of 

 limestones, more or less argillaceous, with beds of red clay, sometimes containing 

 geodes, and having a thickness of 200 to 300 feet. It does not lose its thickness 

 in Kentucky or Tennessee, but becomes more cherty and silicious. It is everywhere 

 cavernous, and abounds in sunken rivers, lost or subterranean streams, and in sur- 

 face, funnel-shaped sink-holes. The Mammoth Cave of Kentucky, and the 

 Wyandotte Cave of Indiana, which has been explored 23 miles, and has a room 

 240 feet high, are in this Group. 



