221 Devonian op Southern Indiana 93 



represented by the closely related species S. texta in the Knob- 

 stone of the Indiana secftion, while the genus is entirel}' unknown 

 in the Rockford limestone. 



In the face of evidence now at hand it seems to us that the 

 Rockford limestone must be considered the equivalent of the 

 Lithographic or Louisiana limestone of the later Missouri reports. 



In a foot note''^ to this paper the authors propose the name 

 "Kinderhook group," to include the beds lying between the 

 Black slate and the Burlington limestone. 



During the year 1862 Prof. Hall was led to change his opinion 

 regarding the Marcellus age of the Rockford Goniatitcs by find- 

 ing the Rockford species G. hyas among fossils from the Waverly 

 of Ohio. This led him to "conclude that the position assigned 

 to the Go7iiatites beds of Rockford may be erroneous and that the 

 true position is higher in the series or more nearly in a parallel 

 with the Chemung group."! 



In 1862 Messrs. White and Whitfield published a paper entitled 

 "Observations upon the Rocks of the Mississippi Vallej' Which 

 Have Been Referred to the Chemung Group of New York, To- 

 gether with Descriptions of New Species of Fossils from the 

 Same Horizon at Burlington, Iowa.";]: The authors state that 

 sufficient fossils have not been found to determine the age of the 

 lower Knob shales in Indiana and Kentuck3^ The fossils of the 

 upper sandstones they consider to be more nearly related to those 

 of the Keokuk than to those of the Burlington limestone or the 

 Chemung rocks of the Mississippi valley. "Barely enough of the 

 fossils of the Burlington limestone are recognized there to show 

 that it is represented." 11 



During the same year Prof. A. Winchell published two papers 

 on the Marshall and Huron groups of Michigan. In one of 

 these§ five species from the Marshall group are identified with 

 fossils previously described from Rockford, Ind. 



In 1862 Prof. Robert Owen^fl designated the sandstones and 



*Am. Jour. Sci., 2d ser., vol. 32, 1861, p. 288. 



ti5th Rept. N. Y. Regents, p. 81. 



iProc. Bost. Soc. Nat. Hist., vol. 8, p. 289. 



||Ib., p. 292. 



^Proc. Acad. Nat. Sci. Phil., 1862, p. 405. 



find. Geol. Rept., 1862, pp. 92, 108, etc. 



