THE CRINOID FAUNA OF THE KNOBSTONE FORIklATION. 



By Frank Springer, 



of Las Vegas, New Mexico. 



In connection with my researches on the fossil Crinoidea I have 

 encountered continual difficulty relative to the stratigraphic posi- 

 tion of a number of important species from the Lower Carboniferous 

 described from southern Indiana, Kentucky, and Tennessee, and 

 found in collections made by Troost, Safford, Lyon, Wachsmuth, 

 Pate, Greene, and others. These species in the descriptions and 

 upon the labels in collections have been referred to a horizon where 

 it has seemed to me increasingly more evident they do not belong. 



Lyon, writing in 1860 on the " Stratigraphical arrangement of 

 the rocks of Kentucky,"^ gave a general section of the strata of 

 western Kentucky, which he divided into beds designated from A to 

 X, in descending order, grouped in two large divisions. The upper 

 of these he called the "Millstone Grit series," including all above the 

 Cavernous (St. Louis) limestone, and the lower the ''Sub-Carboniferous 

 series," in wliich he included the Black slate and the Devonian beds 

 of the Falls of the Ohio. Taking this division above the black 

 slate in ascending order, his beds were: P. Sandstones and shales; 0. 

 Middle limestone; N. Cavernous limestone. The last is clearly the 

 St. Louis limestone of the Missouri and Iowa geologists. His ''Middle 

 limestones," 0, he found to contain in the lower part fossiliferous 

 beds equivalent to the Spergen Hill beds of Indiana (Spergen). 

 His "Sandstones and marls," P, he says are "frequently distinguished 

 as the Knobstone beds," and he describes them as varying in thick- 

 ness from two to three hundred feet, the upper part consisting of 

 "alternate beds of muddy sandstone, aluminous shale, and plates of 

 limestone of variable thickness * * * sometimes largely charged 

 with beds of chert, the lower part of beds of aluminous and marly 

 shale, with occasionally thin beds of fine sandstone." He considers 

 the upper part equivalent to the crinoid beds near Scottville, Allen 

 County; the marly lower beds he says are best known in Bullit and 

 Jefferson counties as "Button-mold Knob." 



1 Trans. Acad. Sci. St. Louis, vol. 1, pp. 612-621. 



Proceedings U. S. National Museum. Vol. 41— No. 1850. 



175 



