223 Devonian of Southern Indiana 95 



Worthen identified the Knobstone of southern Indiana, the 

 argillaceous shales at Cravvfordsville, and abotit "thirt}' feet of 

 greenish-colored shale and shaly sandstone" and thin band of 

 limestone lying below the conglomerate near Williamsport, Ind., 

 with the Keokuk. The sandstones below the limestone band at 

 Williamsport he refers to the Kinderhook on lithological grounds, 

 no fossils being reported from it. The determination of the Keo- 

 kuk age of the formations mentioned above is based by Worthen 

 tipon the presence in them of Spirifcr cuspidatus, Hcviipronitcs 

 crenistria, P. semircticidatus, Orthis viichclini, P. p2tnclatus, and 

 Spirifcr lineatus. 



The equivalency of this fauna with the Keokuk fauna can 

 hardh' be proven by the evidence of the species cited, since not 

 one of them is distin(5fly charadleristic of the Keokuk fauna. 

 Produclus p2uinatus and P. seinireticulatus are known to range 

 throughout the Carboniferous. Spirifer lineatus {Reticularia per- 

 plcxa) is regarded as an Upper Carboniferous species and if pres- 

 ent would tend to indicate a higher horizon for the Knobstone 

 than the Keokuk. It is very probable, however, that Worthen 

 mistook Reticularia pseudolineata (Hall), which is common to the 

 Burlington and Keokuk, for Spirifer lineatus. Spirifer cuspi- 

 datus {Syringothyris carteri) has been reported from both Waverl}- 

 and Burlington faunas, but not from the Keokuk. Hemipronites 

 crenistria (Phillips?) is common to the Lower Carboniferous. 

 Orthis mic/ieli7ii {Rhipidoniella michelini) is recorded from the 

 Waverly, but apparently has never been reported from the Keo- 

 kuk limestone. From this review of Worthen' s evidence of the 

 Keokuk age of the sandstones and shales below the Carboniferous 

 it appears that it points rather to a Burlington or Waverly age 

 for them than to parallelism with the Keokuk. 



In 1869 Prof. A. Winchell published a paper* reviewing the 

 history of the various attempts to correlate the Lower Carbon- 

 iferous formations of the Mississippi valley and summing up the 

 stratigraphical knowledge relative to them. The Knobstone 

 series in Indiana is referred to the Keokuk group. The Rock- 

 ford limestone is said to be represented in northern Indiana by a 

 thin bedded sandstone. It is not quite clear just what sandstone 



^Proc. Am. Phil. Soc, vol. ii, pp. 57-S2. 



