Bemarks iqjon the Kaskaskia Group. 31 



REMARKS UJ'Oj^ THE KASKASKIA GROUP, AXD 



DESCRIPTIONS OF NEW SPECIES OF FOSSILS 



FROM PULASKI COUNTY, KENTUCKY. 



By S. A. Miller, Esq. 



The fossils described in tliis article are referred to the Kaskaskia 

 Group for the following reasons, to-wit: 



Dr. Geo. G. Shumard, who accompanied Marcy's Exploration of the 

 Red River of Louisiana, in 18.^2, and whose remarks npon the general 

 geology of the country passed over by the exploring expedition were 

 published in 1854 (Expl. Red Riv. Lou. p. 156), thus described the 

 geological features of a portion of Northwestern Arkansas: 



" In Washington county we have a fine development of rocks belong- 

 ing to the carboniferous period. I'ising sometimes several hundred feet 

 above the water level of Arkansas River. Thej' consist of beds of 

 dark gray and bluish-gra^- limestone, surmounted by heavy-bedded- 

 coarse and fine grained quartzose sandstone. The ridges of highest 

 elevation run nearly north and south through the center of the countrj^ 

 forming a geological back-bone; the waters from one side flowing east- 

 wardly into White River, and on the other westwardly into Illinois 

 River, both streams being tributaries of the Arkansas. 



" Wherever the limestone forms the surface-rock, the soil is of excel- 

 lent character, and for productiveness is unsurpassed b}' any in the 

 State; but where the sandstone reaches the surface, the soil becomes 

 too arenaceous, and' is of inferior quality for agricultural purposes- 

 The limestone is generally highl}- charged with fossils, and, in man}^ 

 places, beds of considerable thickness are almost entirel}* composed of 

 the remains of crinoidea. 



" In the lithological and palaeontological characters it corresponds 

 very closely to the rocks of the superior division of the carboniferous 

 system of Indiana. Keutuckj', Illinois and Missouri. The fossils are 

 usuall}^ remarkably well preserved. The following are the most 

 abundant and characteristic species: Archimedipora archimedes, Agas- 

 sizocrinus dacfAjliformis, Pentremites sulcatus, Productus cora, P. 

 pimctatus, P. costatus, T'ei'ebratida subtilita, and T. marcyi. We 

 have found all these species associated together in Grayson count}', 

 Kentucky, near Salem, Indiana, and at Chester and Kaskaskia, Ill- 

 inois. 



" The line of junction between the sandstone and limestone is 



