Remarks vpon the Kaskaskia Group. 33 



'•IV. St. Louis limestone, concretionary limestone. 



'^^ Localities. — Highest beds below Keokuk, Iowa; St. Louis, Mis- 

 souri; St. Genevieve. 



"III. Arenaceous bed; second Archimedes, or Warsaw limestone. 



'■'Localities. — Warsaw, above Alton, Illinois; Spergen Hill, Bloom- 

 ington, Indiana. 



"Beds of passnge; soft shal}^ or marh^ bed, with geodes of quartz^ 

 chaleedon}^ etc. 



"II. Keokuk limestone, or lower Archimedes limestone. 



'■'■Localities. — Keokuk, Quiucy, Illinois, etc. 



"Beds of passage; cherty beds 60 to 100 feet. 



"Rapids above Keokuk. 



"I. Burlington limestone. 



'■'■Localities. — Burlington, Iowa; Quincj', Illinois; Hannibal, etc.. 

 Missouri." 



In 1858 Prof. James Hall (Geo. Sur. of Iowa, vol. 1, pt. 2) said: 



" The Kaskaskia limestone, so well developed at Kaskaskia, and 

 thence along the river bottom to Chester, and as far as Fountain Bluff, 

 is unknown up to the present time within the limits of the State of 

 Iowa. I have, nevertheless, felt it my duty to illustrate in some 

 measure its fossil remains, in order to prove its distinctness from the 

 Keokuk limestone, with which it has, heretofore, been identified as 

 the ' Archimedes limestone.' The fossils selected for this purpose are 

 of the same class, and represent the forms, chiefly, of Crinoidea and 

 Brachiopoda, which are most commonly found in these limestones. 

 No species common to the two limestones have been observed by my- 

 self; and though probably such do occur, the^^ arecertainlj^ not numer- 

 ous, nor among the prominent forms which everj'where mark the two 

 rocks." 



He described from the Kaskaskia limestone at Kaskaskia and Chester. 

 Illinois, Scaphiocrinus decabrachiatus, 8. internodius, 8. scopariiis, 

 Zeacrinus intermedium, Z. maniformis.^ Z. loortheni, Agassizocrinus 

 gibbosus, A. constr ictus, Cyathocrinus pentalobus, Dichocrinus pro- 

 tuberans, Acrocrinus urniformis, Pentremites cherokeus, P. cervinus, 

 P. godoni^ P. jpyriformis.^ Agelacrinus kaskaskensis, Arclufocidaris 

 norwoodi, Athyris siiblamellosa, A. subquadrata, Retzia vera, R. vera 

 var costata, Spirifera setigera, 8 spinosa^ 8.. increbescens. Several of 

 these species are mentioned as occurring in Kentuckj^ and other places. 

 Zeacrinus magnoliceformis, Pentremites symmetricus, P. obesus and P. 

 globosus, are mentioned as occurring in the same limestone in Tennessee, 

 Ken tuck V, and elsewhere. 



