542 



PALJEONTOLOGICAL REPORT OE GEOLOGICAL SURVEY. 



dence, since, in the Holloway's boring, near Henderson, Ky., our 11th 

 coal is found also between two strata of limestone, the upper four feet 

 thickj'the^inferior eight feet. Thus the supposition that the Pittsburg 

 vein is represented by the 8th coal, in the western Kentucky coal- 

 fields, is confirmed, since the distance to No. 9 is the same as that mark' 

 ed in Lesley's Manual, between the Pittsburg vein and the 1st coal of 

 the great limestone.* 



Before entering the western coal-fields of Kentucky, we bad good 

 opportunity to study the shales of No. 9 coal, first at the Shawneetown 

 Mining Company's mines, and then at the Saline Company's mines, 

 Illinois. At this last place, especially where the coal is «xtensively 

 worked, we saw the characteristic shells in the shales, especially Avicula 

 reetalateraria and Productus muricatus, with some remains of fishes 

 and large nodules of iron, sometimes perfectly round and of immense 

 size, containing at some places a great number of shells, and even fine 

 pieces of petrified wood. They are especially formed of sulphuret of 

 iron, and so hard that they can only be broken after they have been 

 roasted in the heaps of burning shales. 



Curleto mines, Union county, Kentucky, No. 9, is here the main coal, 

 four feet thick, covered with thick black shales, in which are imbedded 

 large nodules of sulphuret of iron. With the remains of fishes. Avi- 

 cula reetalateraria, is the only shell that we found in the shales, and 

 even it is scarce here. Generally speaking, this shell is. unequally 

 distributed — sometimes extraordinary abundant, and sometimes entire- 

 ly wanting over extensive surfaces. At Curlew mines, the shales con- 

 tain also large pieces of Bigillaria. 



Mulforefs mines, Union county. The main coal here is still No. 9 ; 

 it is four to five feet thick, covered with the same thick black shales 

 as at Curlew, but with a much greater abundance of fossil shells. 

 Avicula reetalateraria, and especially Productus muricatus are accumul- 

 ated in the shales in such quantities that they cover them sometimes 

 entirely. The large nodules of iron, also, of which some had been 

 burnt and broken, were seen to contain quantities of different specks 

 of shells, especially large bivalves and fine pieces of wood. 



JackfieWs coal, at Capt Dams', Hopkins county. Though the coal 

 No. 9 is not worked here, it has been opened and its shales exposed 



•See Lesley's Manual of ths coal, p. 84. 



