278 TRANSACTIONS OF THE [MAR. 15, 



the custom of Ohio geologists to refer the Maxville Limestone 

 to the Kaskaskia group, though its exact horizon has never 

 been definite!}- pointed out. 



The fauna of the Batesville Sandstone is remarkabl}- like 

 that of the Maxville Limestone, particular!}' so when the 

 diverse lithologic characters of the two formations are consid- 

 ered. In both cases the fauna is a mingling of St. Louis and 

 Kaskaskia species, and from the paleontologic evidence alone, 

 the two formations may well be correlated. 



The following nine Batesville Sandstone species are present, 

 or have their nearest allies, in the Maxville Limestone. 



Productus cestriensis. 



Spirifer keokuk. 



Athyris subquadrata. 



Dielasma turgid a, var. elongata. 



Pinna arkansana. 



AlloiHsma icalkeri. 



Schizodus batesvillensis. 



Bellerophon sublaevis. 



Straparollus similis? 



Stratigraphic Correlation. 



Stratigraphy of the Mississippian Series in the Batesville 



Region. 



The following section of the Mississippian rocks in the Bates- 

 ville region of Arkansas is compiled from the published reports 

 of the Geological Survey of Arkansas and from the field obser- 

 vations of the author. The formations are discussed consecu- 

 tively, beginning with the lowermost. 



1. Sylamore Sandstone. — This formation is irregular in its 

 distribution, sometimes being absent and at other times reach- 

 ing a thickness of from thirty to forty feet. It is more exten- 

 sively developed in the counties further west than in the im- 

 mediate Batesville region. It is a bed of brown, yellow or gray 

 sandstone, often with interstratified green or black shaly layers, 

 and frequently containing small flat or rounded ferruginous 

 concretions. In some localities the sandstone is wholly re- 

 placed by a black shale. 



2. St. Joe Marble. — This formation is ordinai'ily a red crys- 

 talline limestone with an average thickness of from twenty-five 

 to forty feet. In many localities the red fades through a 

 mottled to a bluish gray color. Chert bands are often inter- 

 stratified. Fossils are not abundant but such as are present 

 point to the Kinderhook age of the formation. 



