1897.] NEW YORK ACADEMY OF SCIENCES. 281 



4. St. Louis Limestone. — This is a widely distributed forma- 

 tion consisting of a more or less pure limestone, variable in its 

 characters, often oolitic and sometimes wholh' or partiall}' re- 

 l)laced b}^ marly deposits. The St. Louis Limestone varies in 

 thickness from fifty to two hundred feet. 



5. Aux Vases Sandstone. — This name has been applied by 

 Ke\-es* to the basal sandstone member of the Kaskaskia group. 

 It is generally a thick-bedded sandstone, fine-grained and homo- 

 geneous in texture; it is iron-stained and has a soft brown color 

 or is mottled in appearance. In southern Illinois, where this 

 formation is typicall}' developed, it is one hundred or more feet 

 in thickness. Is'o fossils have ever been found in it. 



6. Kaskaskia Limestones and Shales. — Between the Aux 

 Yases Sandstone below and the basal conglomerate of the Coal 

 Measures above there is a series of from five to eight hundred 

 feet of interbedded limestones, shales and sandstones, as the 

 formation is typically- developed in southern Illinois. 



ComiDarison of the two Sections. 



On a critical comparison of these two Mississippian sections 

 their similiarity is most striking, and in the following table may 

 be seen the equivalent strata in the two sections. 



Batesville Section. 



Typical Section. 



1. Sylamore Sandstone. 



2. St. Joe Marble. 



3. Boone Chert. 



4. Spring Creek Limestone and Shale. 



5. Batesville Sandstone. 



6. Boston Group. 



1. Basal Sandstone of the Kinderbook 



Group. 



2. Kinderbook Group. 



3. Osage Group. 



4. St. Louis Lime-tone. 



5. Aux Vases Sandstone. 



6. Kaskaskia Limestone and Sbales. 



The Batesville Sandstone has the same stratigraphic position 

 in the Batesville section which the Aux Yases Sandstone occu- 

 pies in the tj'pical section, and the lithologic characters of the two 

 formations are similar. No fossils have as yet been found in 

 the Aux Yases Sandstone, but if a fauna were found, a ming- 

 ling of St. Louis and Kaskaskia species, such as ai"e present in 

 the Batesville Sandstone fauna, would be looked for. 



The strata of the Batesville section were deposited off the 

 southern shore of the same land, from whose eastern shore 

 the strata of the t\'pical section were laid down; hence, it is not 

 surprising to find the sequence of the strata almost identical in 

 the two sections. 



*Bull. Geol. Soc. Am., Vol. 3, p. 295, and Geol. Surv. Mo., Vol. 4, p. 72. 



