Remarks upon the Kaskaskia Group. 35 



Muddy River, iu laoksou coimly, to Prairie du Rocher, in Randolph 

 county, conliruiing to his entire satisfaction the correctness of the 

 section previously made. Holding a subordinate position in the sur- 

 vey, I did not feel at liberty to publish the facts I observed in the 

 prosecution of my labors in the field, and as they were not announced 

 by tiie Chief of the Survey', who alone had the authority to make 

 known the scientific results attained in the prosecution of the work, 

 these facts remained unknown, except to the members of the Illinois 

 corps. 



" On the appearance of the Missouri Report, in 1855, in which all the 

 limestones, containing the screw-shaped fossil known as Archimedes., 

 were grouped together under the name of Archimedes limestone, and 

 placed below the St. Louis limestone, I informed Prof. Hall, with 

 whom I was then engaged in the Iowa Survey, of the result of the ob- 

 servations 1 had previously made, in Illinois, and the true sequence of 

 the strata, as determined in the section above named, and he at once 

 proposed that, at the conclusion of our field labors in Iowa for that 

 season, we should go to Randolph county, that he might vei-ifj' by per- 

 sonal observation the conclusions at which I had arrived. Accord- 

 ingly, in October of that year, we went together to that county, and 

 for the third time I traced the bluffs, on foot, from Prairie du Rocher 

 to Chester, and for the second time A'erified the results of m3' first ex- 

 amination. In the following year (1856), Prof. Hall read a paper be- 

 fore a meeting of the Albany Institute, in which the subdivisions of 

 the sub-carboniferous limestones are given substantially as they sub- 

 sequently appeared in the Iowa Report. His reasons for substituting 

 the name of Kaskaskia for Chester limestone do not appear, and we 

 prefer to retain the name first given to it, when its true position in the 

 series was determined." 



It follows from what has been said that the name Kaskaskia lime- 

 stone has by publication ten years' priority over Chester limestone., and 

 that while Prof. Worthen was an independent discoverer of the true 

 position of these rocks, that he was nevertheless a year behind Dr. 

 Geo. G. Shumard in determining their position, and twelve years be- 

 hind him in publishing such determination. Moreover, Dr. Shumard 

 had, at that early time, determined their extent and distribution, not 

 only over a small area in the State of Illinois, but in Missouri, Arkan- 

 sas, Indiana and Kentucky. 



In conclusion, it is evident that by all the rules governing scientific no- 

 menclature, in matters of priority, the name Chester limestone or Ches. 

 fer Group must be stricken out because it is a s3'nou3'm for Kaskaskia 



